Fix CA1852

.editorconfig

@@ -772,6 +772,9 @@ dotnet_diagnostic.CA1849.severity = warning
 # Prefer static HashData method over ComputeHash. (Not available on mono)
 dotnet_diagnostic.CA1850.severity = none
 
+# Seal internal types.
+dotnet_diagnostic.CA1852.severity = warning
+
 # Unnecessary call to 'Dictionary.ContainsKey(key)'.
 dotnet_diagnostic.CA1853.severity = warning
 

OpenRA.Game/Actor.cs

@@ -81,7 +81,7 @@ namespace OpenRA
 		/// <summary>Value used to represent an invalid token.</summary>
 		public static readonly int InvalidConditionToken = -1;
 
-		class ConditionState
+		sealed class ConditionState
 		{
 			/// <summary>Delegates that have registered to be notified when this condition changes.</summary>
 			public readonly List<VariableObserverNotifier> Notifiers = new();

OpenRA.Game/FileSystem/ZipFile.cs

@@ -190,7 +190,7 @@ namespace OpenRA.FileSystem
 			public void Dispose() { /* nothing to do */ }
 		}
 
-		class StaticStreamDataSource : IStaticDataSource
+		sealed class StaticStreamDataSource : IStaticDataSource
 		{
 			readonly Stream s;
 			public StaticStreamDataSource(Stream s)

OpenRA.Game/Graphics/CursorManager.cs

@@ -17,7 +17,7 @@ namespace OpenRA.Graphics
 {
 	public sealed class CursorManager
 	{
-		class Cursor
+		sealed class Cursor
 		{
 			public string Name;
 			public int2 PaddedSize;

OpenRA.Game/Graphics/Model.cs

@@ -62,7 +62,7 @@ namespace OpenRA.Graphics
 	{
 		public Action<string> OnMissingModelError { get; set; }
 
-		class PlaceholderModelCache : IModelCache
+		sealed class PlaceholderModelCache : IModelCache
 		{
 			public IVertexBuffer<Vertex> VertexBuffer => throw new NotImplementedException();
 

OpenRA.Game/Graphics/Palette.cs

@@ -40,7 +40,7 @@ namespace OpenRA.Graphics
 			return new ReadOnlyPalette(palette);
 		}
 
-		class ReadOnlyPalette : IPalette
+		sealed class ReadOnlyPalette : IPalette
 		{
 			readonly IPalette palette;
 			public ReadOnlyPalette(IPalette palette) { this.palette = palette; }

OpenRA.Game/Graphics/SpriteFont.cs

@@ -427,7 +427,7 @@ namespace OpenRA.Graphics
 		}
 	}
 
-	class GlyphInfo
+	sealed class GlyphInfo
 	{
 		public float Advance;
 		public int2 Offset;

OpenRA.Game/Map/Map.cs

@@ -65,7 +65,7 @@ namespace OpenRA
 		MissionSelector = 4
 	}
 
-	class MapField
+	sealed class MapField
 	{
 		enum Type { Normal, NodeList, MiniYaml }
 		readonly FieldInfo field;

OpenRA.Game/Map/MapPreview.cs

@@ -64,7 +64,7 @@ namespace OpenRA
 	public class MapPreview : IDisposable, IReadOnlyFileSystem
 	{
 		/// <summary>Wrapper that enables map data to be replaced in an atomic fashion.</summary>
-		class InnerData
+		sealed class InnerData
 		{
 			public int MapFormat;
 			public string Title;

OpenRA.Game/Network/GeoIP.cs

@@ -21,7 +21,7 @@ namespace OpenRA.Network
 {
 	public class GeoIP
 	{
-		class IP2LocationReader
+		sealed class IP2LocationReader
 		{
 			public readonly DateTime Date;
 			readonly Stream stream;

OpenRA.Game/Network/ReplayConnection.cs

@@ -18,7 +18,7 @@ namespace OpenRA.Network
 {
 	public sealed class ReplayConnection : IConnection
 	{
-		class Chunk
+		sealed class Chunk
 		{
 			public int Frame;
 			public (int ClientId, byte[] Packet)[] Packets;

OpenRA.Game/Network/SyncReport.cs

@@ -19,7 +19,7 @@ using OpenRA.Primitives;
 
 namespace OpenRA.Network
 {
-	class SyncReport
+	sealed class SyncReport
 	{
 		const int NumSyncReports = 7;
 		static readonly Cache<Type, TypeInfo> TypeInfoCache = new(t => new TypeInfo(t));
@@ -161,7 +161,7 @@ namespace OpenRA.Network
 				Log.Write("sync", $"Recorded frames do not contain the frame {frame}. No sync report available!");
 		}
 
-		class Report
+		sealed class Report
 		{
 			public int Frame;
 			public int SyncedRandom;

OpenRA.Game/Server/PlayerMessageTracker.cs

@@ -14,7 +14,7 @@ using System.Collections.Generic;
 
 namespace OpenRA.Server
 {
-	class PlayerMessageTracker
+	sealed class PlayerMessageTracker
 	{
 		[TranslationReference("remaining")]
 		const string ChatTemporaryDisabled = "notification-chat-temp-disabled";

OpenRA.Game/Server/Server.cs

@@ -1441,7 +1441,7 @@ namespace OpenRA.Server
 
 		interface IServerEvent { void Invoke(Server server); }
 
-		class ConnectionConnectEvent : IServerEvent
+		sealed class ConnectionConnectEvent : IServerEvent
 		{
 			readonly Socket socket;
 			public ConnectionConnectEvent(Socket socket)
@@ -1455,7 +1455,7 @@ namespace OpenRA.Server
 			}
 		}
 
-		class ConnectionDisconnectEvent : IServerEvent
+		sealed class ConnectionDisconnectEvent : IServerEvent
 		{
 			readonly Connection connection;
 			public ConnectionDisconnectEvent(Connection connection)
@@ -1469,7 +1469,7 @@ namespace OpenRA.Server
 			}
 		}
 
-		class ConnectionPacketEvent : IServerEvent
+		sealed class ConnectionPacketEvent : IServerEvent
 		{
 			readonly Connection connection;
 			readonly int frame;
@@ -1488,7 +1488,7 @@ namespace OpenRA.Server
 			}
 		}
 
-		class ConnectionPingEvent : IServerEvent
+		sealed class ConnectionPingEvent : IServerEvent
 		{
 			readonly Connection connection;
 			readonly int[] pingHistory;
@@ -1511,7 +1511,7 @@ namespace OpenRA.Server
 			}
 		}
 
-		class CallbackEvent : IServerEvent
+		sealed class CallbackEvent : IServerEvent
 		{
 			readonly Action action;
 

OpenRA.Game/Support/AssemblyLoader.cs

@@ -97,7 +97,7 @@ namespace OpenRA.Support
 		}
 	}
 
-	class ManagedLoadContext : AssemblyLoadContext
+	sealed class ManagedLoadContext : AssemblyLoadContext
 	{
 		readonly string basePath;
 		readonly Dictionary<string, ManagedLibrary> managedAssemblies;

OpenRA.Game/Support/Benchmark.cs

@@ -14,7 +14,7 @@ using System.Globalization;
 
 namespace OpenRA.Support
 {
-	class Benchmark
+	sealed class Benchmark
 	{
 		readonly string prefix;
 		readonly Dictionary<string, List<BenchmarkPoint>> samples = new();
@@ -30,7 +30,7 @@ namespace OpenRA.Support
 				samples.GetOrAdd(item.Key).Add(new BenchmarkPoint(localTick, item.Value.LastValue));
 		}
 
-		class BenchmarkPoint
+		sealed class BenchmarkPoint
 		{
 			public int Tick { get; }
 			public double Value { get; }

OpenRA.Game/Support/VariableExpression.cs

@@ -551,7 +551,7 @@ namespace OpenRA.Support
 			}
 		}
 
-		class VariableToken : Token
+		sealed class VariableToken : Token
 		{
 			public readonly string Name;
 
@@ -561,7 +561,7 @@ namespace OpenRA.Support
 				: base(TokenType.Variable, index) { Name = symbol; }
 		}
 
-		class NumberToken : Token
+		sealed class NumberToken : Token
 		{
 			public readonly int Value;
 			readonly string symbol;
@@ -714,7 +714,7 @@ namespace OpenRA.Support
 			return Expressions.Expression.Condition(test, ifTrue, ifFalse);
 		}
 
-		class AstStack
+		sealed class AstStack
 		{
 			readonly List<Expression> expressions = new();
 			readonly List<ExpressionType> types = new();
@@ -772,7 +772,7 @@ namespace OpenRA.Support
 			}
 		}
 
-		class Compiler
+		sealed class Compiler
 		{
 			readonly AstStack ast = new();
 

OpenRA.Game/TraitDictionary.cs

@@ -39,7 +39,7 @@ namespace OpenRA
 	/// <summary>
 	/// Provides efficient ways to query a set of actors by their traits.
 	/// </summary>
-	class TraitDictionary
+	sealed class TraitDictionary
 	{
 		static readonly Func<Type, ITraitContainer> CreateTraitContainer = t =>
 			(ITraitContainer)typeof(TraitContainer<>).MakeGenericType(t).GetConstructor(Type.EmptyTypes).Invoke(null);
@@ -141,7 +141,7 @@ namespace OpenRA
 			int Queries { get; }
 		}
 
-		class TraitContainer<T> : ITraitContainer
+		sealed class TraitContainer<T> : ITraitContainer
 		{
 			readonly List<Actor> actors = new();
 			readonly List<T> traits = new();
@@ -185,7 +185,7 @@ namespace OpenRA
 				return new MultipleEnumerable(this, actor);
 			}
 
-			class MultipleEnumerable : IEnumerable<T>
+			sealed class MultipleEnumerable : IEnumerable<T>
 			{
 				readonly TraitContainer<T> container;
 				readonly uint actor;

OpenRA.Game/Traits/Player/Shroud.cs

@@ -76,7 +76,7 @@ namespace OpenRA.Traits
 		public int RevealedCells { get; private set; }
 
 		enum ShroudCellType : byte { Shroud, Fog, Visible }
-		class ShroudSource
+		sealed class ShroudSource
 		{
 			public readonly SourceType Type;
 			public readonly PPos[] ProjectedCells;

OpenRA.Game/UtilityCommands/ClearInvalidModRegistrationsCommand.cs

@@ -13,7 +13,7 @@ using System.Linq;
 
 namespace OpenRA.UtilityCommands
 {
-	class ClearInvalidModRegistrationsCommand : IUtilityCommand
+	sealed class ClearInvalidModRegistrationsCommand : IUtilityCommand
 	{
 		string IUtilityCommand.Name => "--clear-invalid-mod-registrations";
 

OpenRA.Game/UtilityCommands/RegisterModCommand.cs

@@ -13,7 +13,7 @@ using System.Linq;
 
 namespace OpenRA.UtilityCommands
 {
-	class RegisterModCommand : IUtilityCommand
+	sealed class RegisterModCommand : IUtilityCommand
 	{
 		string IUtilityCommand.Name => "--register-mod";
 

OpenRA.Game/UtilityCommands/UnregisterModCommand.cs

@@ -13,7 +13,7 @@ using System.Linq;
 
 namespace OpenRA.UtilityCommands
 {
-	class UnregisterModCommand : IUtilityCommand
+	sealed class UnregisterModCommand : IUtilityCommand
 	{
 		string IUtilityCommand.Name => "--unregister-mod";
 

OpenRA.Mods.Cnc/Activities/Infiltrate.cs

@@ -18,7 +18,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Activities
 {
-	class Infiltrate : Enter
+	sealed class Infiltrate : Enter
 	{
 		readonly Infiltrates infiltrates;
 		readonly INotifyInfiltration[] notifiers;

OpenRA.Mods.Cnc/Effects/GpsDotEffect.cs

@@ -19,7 +19,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Effects
 {
-	class GpsDotEffect : IEffect, IEffectAnnotation
+	sealed class GpsDotEffect : IEffect, IEffectAnnotation
 	{
 		readonly Actor actor;
 		readonly GpsDotInfo info;
@@ -28,7 +28,7 @@ namespace OpenRA.Mods.Cnc.Effects
 		readonly PlayerDictionary<DotState> dotStates;
 		readonly IVisibilityModifier[] visibilityModifiers;
 
-		class DotState
+		sealed class DotState
 		{
 			public readonly GpsWatcher Watcher;
 			public readonly bool FrozenActorWithRenderables;

OpenRA.Mods.Cnc/Effects/GpsSatellite.cs

@@ -16,7 +16,7 @@ using OpenRA.Mods.Cnc.Traits;
 
 namespace OpenRA.Mods.Cnc.Effects
 {
-	class GpsSatellite : IEffect, ISpatiallyPartitionable
+	sealed class GpsSatellite : IEffect, ISpatiallyPartitionable
 	{
 		readonly Player launcher;
 		readonly Animation anim;

OpenRA.Mods.Cnc/Effects/SatelliteLaunch.cs

@@ -16,7 +16,7 @@ using OpenRA.Mods.Cnc.Traits;
 
 namespace OpenRA.Mods.Cnc.Effects
 {
-	class SatelliteLaunch : IEffect, ISpatiallyPartitionable
+	sealed class SatelliteLaunch : IEffect, ISpatiallyPartitionable
 	{
 		readonly GpsPowerInfo info;
 		readonly Actor launcher;

OpenRA.Mods.Cnc/FileFormats/Blowfish.cs

@@ -11,7 +11,7 @@
 
 namespace OpenRA.Mods.Cnc.FileFormats
 {
-	class Blowfish
+	sealed class Blowfish
 	{
 		public Blowfish(byte[] key)
 		{

OpenRA.Mods.Cnc/FileFormats/BlowfishKeyProvider.cs

@@ -16,11 +16,11 @@ namespace OpenRA.Mods.Cnc.FileFormats
 {
 	/* TODO: Convert this direct C port into readable code. */
 
-	class BlowfishKeyProvider
+	sealed class BlowfishKeyProvider
 	{
 		const string PublicKeyString = "AihRvNoIbTn85FZRYNZRcT+i6KpU+maCsEqr3Q5q+LDB5tH7Tz2qQ38V";
 
-		class PublicKey
+		sealed class PublicKey
 		{
 			public readonly uint[] KeyOne = new uint[64];
 			public readonly uint[] KeyTwo = new uint[64];

OpenRA.Mods.Cnc/FileSystem/BigFile.cs

@@ -61,7 +61,7 @@ namespace OpenRA.Mods.Cnc.FileSystem
 				}
 			}
 
-			class Entry
+			sealed class Entry
 			{
 				public readonly uint Offset;
 				public readonly uint Size;

OpenRA.Mods.Cnc/Graphics/TeslaZapRenderable.cs

@@ -17,7 +17,7 @@ using OpenRA.Primitives;
 
 namespace OpenRA.Mods.Cnc.Graphics
 {
-	class TeslaZapRenderable : IPalettedRenderable, IFinalizedRenderable
+	sealed class TeslaZapRenderable : IPalettedRenderable, IFinalizedRenderable
 	{
 		static readonly int[][] Steps = new[]
 		{

OpenRA.Mods.Cnc/SpriteLoaders/ShpD2Loader.cs

@@ -28,7 +28,7 @@ namespace OpenRA.Mods.Cnc.SpriteLoaders
 			VariableLengthTable = 4
 		}
 
-		class ShpD2Frame : ISpriteFrame
+		sealed class ShpD2Frame : ISpriteFrame
 		{
 			public SpriteFrameType Type => SpriteFrameType.Indexed8;
 			public Size Size { get; }

OpenRA.Mods.Cnc/SpriteLoaders/ShpTDLoader.cs

@@ -75,7 +75,7 @@ namespace OpenRA.Mods.Cnc.SpriteLoaders
 	{
 		enum Format { XORPrev = 0x20, XORLCW = 0x40, LCW = 0x80 }
 
-		class ImageHeader : ISpriteFrame
+		sealed class ImageHeader : ISpriteFrame
 		{
 			public SpriteFrameType Type => SpriteFrameType.Indexed8;
 			public Size Size => reader.Size;

OpenRA.Mods.Cnc/SpriteLoaders/TmpRALoader.cs

@@ -18,7 +18,7 @@ namespace OpenRA.Mods.Cnc.SpriteLoaders
 {
 	public class TmpRALoader : ISpriteLoader
 	{
-		class TmpRAFrame : ISpriteFrame
+		sealed class TmpRAFrame : ISpriteFrame
 		{
 			public SpriteFrameType Type => SpriteFrameType.Indexed8;
 			public Size Size { get; }

OpenRA.Mods.Cnc/SpriteLoaders/TmpTDLoader.cs

@@ -18,7 +18,7 @@ namespace OpenRA.Mods.Cnc.SpriteLoaders
 {
 	public class TmpTDLoader : ISpriteLoader
 	{
-		class TmpTDFrame : ISpriteFrame
+		sealed class TmpTDFrame : ISpriteFrame
 		{
 			public SpriteFrameType Type => SpriteFrameType.Indexed8;
 			public Size Size { get; }

OpenRA.Mods.Cnc/SpriteLoaders/TmpTSLoader.cs

@@ -18,7 +18,7 @@ namespace OpenRA.Mods.Cnc.SpriteLoaders
 {
 	public class TmpTSLoader : ISpriteLoader
 	{
-		class TmpTSDepthFrame : ISpriteFrame
+		sealed class TmpTSDepthFrame : ISpriteFrame
 		{
 			readonly TmpTSFrame parent;
 
@@ -35,7 +35,7 @@ namespace OpenRA.Mods.Cnc.SpriteLoaders
 			}
 		}
 
-		class TmpTSFrame : ISpriteFrame
+		sealed class TmpTSFrame : ISpriteFrame
 		{
 			public SpriteFrameType Type => SpriteFrameType.Indexed8;
 			public Size Size { get; }

OpenRA.Mods.Cnc/Traits/Attack/AttackPopupTurreted.cs

@@ -18,7 +18,7 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[Desc("Actor's turret rises from the ground before attacking.")]
-	class AttackPopupTurretedInfo : AttackTurretedInfo, Requires<BuildingInfo>, Requires<WithEmbeddedTurretSpriteBodyInfo>
+	sealed class AttackPopupTurretedInfo : AttackTurretedInfo, Requires<BuildingInfo>, Requires<WithEmbeddedTurretSpriteBodyInfo>
 	{
 		[Desc("How many game ticks should pass before closing the actor's turret.")]
 		public readonly int CloseDelay = 125;
@@ -46,7 +46,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new AttackPopupTurreted(init, this); }
 	}
 
-	class AttackPopupTurreted : AttackTurreted, INotifyIdle, IDamageModifier
+	sealed class AttackPopupTurreted : AttackTurreted, INotifyIdle, IDamageModifier
 	{
 		enum PopupState { Open, Rotating, Transitioning, Closed }
 

OpenRA.Mods.Cnc/Traits/Attack/AttackTDGunboatTurreted.cs

@@ -34,7 +34,7 @@ namespace OpenRA.Mods.Cnc.Traits
 			return new AttackTDGunboatTurretedActivity(self, newTarget, forceAttack, targetLineColor);
 		}
 
-		class AttackTDGunboatTurretedActivity : Activity
+		sealed class AttackTDGunboatTurretedActivity : Activity
 		{
 			readonly AttackTDGunboatTurreted attack;
 			readonly Target target;

OpenRA.Mods.Cnc/Traits/Attack/AttackTesla.cs

@@ -19,7 +19,7 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[Desc("Implements the charge-then-burst attack logic specific to the RA tesla coil.")]
-	class AttackTeslaInfo : AttackBaseInfo
+	sealed class AttackTeslaInfo : AttackBaseInfo
 	{
 		[Desc("How many charges this actor has to attack with, once charged.")]
 		public readonly int MaxCharges = 1;
@@ -39,7 +39,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new AttackTesla(init.Self, this); }
 	}
 
-	class AttackTesla : AttackBase, ITick, INotifyAttack
+	sealed class AttackTesla : AttackBase, ITick, INotifyAttack
 	{
 		readonly AttackTeslaInfo info;
 
@@ -83,7 +83,7 @@ namespace OpenRA.Mods.Cnc.Traits
 			return new ChargeAttack(this, newTarget, forceAttack, targetLineColor);
 		}
 
-		class ChargeAttack : Activity, IActivityNotifyStanceChanged
+		sealed class ChargeAttack : Activity, IActivityNotifyStanceChanged
 		{
 			readonly AttackTesla attack;
 			readonly Target target;
@@ -144,7 +144,7 @@ namespace OpenRA.Mods.Cnc.Traits
 			}
 		}
 
-		class ChargeFire : Activity
+		sealed class ChargeFire : Activity
 		{
 			readonly AttackTesla attack;
 			readonly Target target;

OpenRA.Mods.Cnc/Traits/Disguise.cs

@@ -20,12 +20,12 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[Desc("Overrides the default Tooltip when this actor is disguised (aids in deceiving enemy players).")]
-	class DisguiseTooltipInfo : TooltipInfo, Requires<DisguiseInfo>
+	sealed class DisguiseTooltipInfo : TooltipInfo, Requires<DisguiseInfo>
 	{
 		public override object Create(ActorInitializer init) { return new DisguiseTooltip(init.Self, this); }
 	}
 
-	class DisguiseTooltip : ConditionalTrait<DisguiseTooltipInfo>, ITooltip
+	sealed class DisguiseTooltip : ConditionalTrait<DisguiseTooltipInfo>, ITooltip
 	{
 		readonly Actor self;
 		readonly Disguise disguise;
@@ -64,7 +64,7 @@ namespace OpenRA.Mods.Cnc.Traits
 	}
 
 	[Desc("Provides access to the disguise command, which makes the actor appear to be another player's actor.")]
-	class DisguiseInfo : TraitInfo
+	sealed class DisguiseInfo : TraitInfo
 	{
 		[VoiceReference]
 		public readonly string Voice = "Action";
@@ -98,7 +98,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new Disguise(init.Self, this); }
 	}
 
-	class Disguise : IEffectiveOwner, IIssueOrder, IResolveOrder, IOrderVoice, IRadarColorModifier, INotifyAttack,
+	sealed class Disguise : IEffectiveOwner, IIssueOrder, IResolveOrder, IOrderVoice, IRadarColorModifier, INotifyAttack,
 		INotifyDamage, INotifyUnload, INotifyDemolition, INotifyInfiltration, ITick
 	{
 		public ActorInfo AsActor { get; private set; }
@@ -280,7 +280,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		}
 	}
 
-	class DisguiseOrderTargeter : UnitOrderTargeter
+	sealed class DisguiseOrderTargeter : UnitOrderTargeter
 	{
 		readonly DisguiseInfo info;
 

OpenRA.Mods.Cnc/Traits/FrozenUnderFogUpdatedByGps.cs

@@ -44,7 +44,7 @@ namespace OpenRA.Mods.Cnc.Traits
 			gps.UnregisterForOnGpsRefreshed(fufubg.self, fufubg);
 		};
 
-		class Traits
+		sealed class Traits
 		{
 			public readonly FrozenActorLayer FrozenActorLayer;
 			public readonly GpsWatcher GpsWatcher;

OpenRA.Mods.Cnc/Traits/GpsDot.cs

@@ -15,7 +15,7 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[Desc("Show an indicator revealing the actor underneath the fog when a GPSWatcher is activated.")]
-	class GpsDotInfo : TraitInfo
+	sealed class GpsDotInfo : TraitInfo
 	{
 		[Desc("Sprite collection for symbols.")]
 		public readonly string Image = "gpsdot";
@@ -30,7 +30,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new GpsDot(this); }
 	}
 
-	class GpsDot : INotifyCreated, INotifyAddedToWorld, INotifyRemovedFromWorld
+	sealed class GpsDot : INotifyCreated, INotifyAddedToWorld, INotifyRemovedFromWorld
 	{
 		readonly GpsDotInfo info;
 		GpsDotEffect effect;

OpenRA.Mods.Cnc/Traits/GpsWatcher.cs

@@ -18,14 +18,14 @@ namespace OpenRA.Mods.Cnc.Traits
 {
 	[TraitLocation(SystemActors.Player)]
 	[Desc("Required for `GpsPower`. Attach this to the player actor.")]
-	class GpsWatcherInfo : TraitInfo
+	sealed class GpsWatcherInfo : TraitInfo
 	{
 		public override object Create(ActorInitializer init) { return new GpsWatcher(init.Self.Owner); }
 	}
 
 	interface IOnGpsRefreshed { void OnGpsRefresh(Actor self, Player player); }
 
-	class GpsWatcher : ISync, IPreventsShroudReset
+	sealed class GpsWatcher : ISync, IPreventsShroudReset
 	{
 		[Sync]
 		public bool Launched { get; private set; }

OpenRA.Mods.Cnc/Traits/Infiltration/InfiltrateForCash.cs

@@ -18,7 +18,7 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[Desc("Funds are transferred from the owner to the infiltrator.")]
-	class InfiltrateForCashInfo : TraitInfo
+	sealed class InfiltrateForCashInfo : TraitInfo
 	{
 		[Desc("The `TargetTypes` from `Targetable` that are allowed to enter.")]
 		public readonly BitSet<TargetableType> Types = default;
@@ -53,7 +53,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new InfiltrateForCash(this); }
 	}
 
-	class InfiltrateForCash : INotifyInfiltrated
+	sealed class InfiltrateForCash : INotifyInfiltrated
 	{
 		readonly InfiltrateForCashInfo info;
 

OpenRA.Mods.Cnc/Traits/Infiltration/InfiltrateForDecoration.cs

@@ -19,7 +19,7 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[Desc("Reveals a decoration sprite to the indicated players when infiltrated.")]
-	class InfiltrateForDecorationInfo : WithDecorationInfo
+	sealed class InfiltrateForDecorationInfo : WithDecorationInfo
 	{
 		[Desc("The `TargetTypes` from `Targetable` that are allowed to enter.")]
 		public readonly BitSet<TargetableType> Types = default;
@@ -27,7 +27,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new InfiltrateForDecoration(init.Self, this); }
 	}
 
-	class InfiltrateForDecoration : WithDecoration, INotifyInfiltrated
+	sealed class InfiltrateForDecoration : WithDecoration, INotifyInfiltrated
 	{
 		readonly HashSet<Player> infiltrators = new();
 		readonly InfiltrateForDecorationInfo info;

OpenRA.Mods.Cnc/Traits/Infiltration/InfiltrateForExploration.cs

@@ -17,7 +17,7 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[Desc("Steal and reset the owner's exploration.")]
-	class InfiltrateForExplorationInfo : TraitInfo
+	sealed class InfiltrateForExplorationInfo : TraitInfo
 	{
 		[Desc("The `TargetTypes` from `Targetable` that are allowed to enter.")]
 		public readonly BitSet<TargetableType> Types = default;
@@ -39,7 +39,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new InfiltrateForExploration(this); }
 	}
 
-	class InfiltrateForExploration : INotifyInfiltrated
+	sealed class InfiltrateForExploration : INotifyInfiltrated
 	{
 		readonly InfiltrateForExplorationInfo info;
 

OpenRA.Mods.Cnc/Traits/Infiltration/InfiltrateForPowerOutage.cs

@@ -15,7 +15,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits
 {
-	class InfiltrateForPowerOutageInfo : TraitInfo
+	sealed class InfiltrateForPowerOutageInfo : TraitInfo
 	{
 		[Desc("The `TargetTypes` from `Targetable` that are allowed to enter.")]
 		public readonly BitSet<TargetableType> Types = default;
@@ -40,7 +40,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new InfiltrateForPowerOutage(init.Self, this); }
 	}
 
-	class InfiltrateForPowerOutage : INotifyOwnerChanged, INotifyInfiltrated
+	sealed class InfiltrateForPowerOutage : INotifyOwnerChanged, INotifyInfiltrated
 	{
 		readonly InfiltrateForPowerOutageInfo info;
 		PowerManager playerPower;

OpenRA.Mods.Cnc/Traits/Infiltration/InfiltrateForSupportPower.cs

@@ -15,7 +15,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits
 {
-	class InfiltrateForSupportPowerInfo : TraitInfo
+	sealed class InfiltrateForSupportPowerInfo : TraitInfo
 	{
 		[ActorReference]
 		[FieldLoader.Require]
@@ -41,7 +41,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new InfiltrateForSupportPower(this); }
 	}
 
-	class InfiltrateForSupportPower : INotifyInfiltrated
+	sealed class InfiltrateForSupportPower : INotifyInfiltrated
 	{
 		readonly InfiltrateForSupportPowerInfo info;
 

OpenRA.Mods.Cnc/Traits/Infiltration/InfiltrateForSupportPowerReset.cs

@@ -16,7 +16,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits
 {
-	class InfiltrateForSupportPowerResetInfo : TraitInfo
+	sealed class InfiltrateForSupportPowerResetInfo : TraitInfo
 	{
 		[Desc("The `TargetTypes` from `Targetable` that are allowed to enter.")]
 		public readonly BitSet<TargetableType> Types = default;
@@ -38,7 +38,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new InfiltrateForSupportPowerReset(this); }
 	}
 
-	class InfiltrateForSupportPowerReset : INotifyInfiltrated
+	sealed class InfiltrateForSupportPowerReset : INotifyInfiltrated
 	{
 		readonly InfiltrateForSupportPowerResetInfo info;
 

OpenRA.Mods.Cnc/Traits/Infiltration/InfiltrateForTransform.cs

@@ -18,7 +18,7 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[Desc("Transform into a different actor type.")]
-	class InfiltrateForTransformInfo : TraitInfo
+	sealed class InfiltrateForTransformInfo : TraitInfo
 	{
 		[ActorReference]
 		[FieldLoader.Require]
@@ -34,7 +34,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new InfiltrateForTransform(init, this); }
 	}
 
-	class InfiltrateForTransform : INotifyInfiltrated
+	sealed class InfiltrateForTransform : INotifyInfiltrated
 	{
 		readonly InfiltrateForTransformInfo info;
 		readonly string faction;

OpenRA.Mods.Cnc/Traits/Infiltration/Infiltrates.cs

@@ -127,7 +127,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		}
 	}
 
-	class InfiltrationOrderTargeter : UnitOrderTargeter
+	sealed class InfiltrationOrderTargeter : UnitOrderTargeter
 	{
 		readonly InfiltratesInfo info;
 

OpenRA.Mods.Cnc/Traits/MadTank.cs

@@ -21,7 +21,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits
 {
-	class MadTankInfo : TraitInfo, IRulesetLoaded, Requires<ExplodesInfo>, Requires<WithFacingSpriteBodyInfo>
+	sealed class MadTankInfo : TraitInfo, IRulesetLoaded, Requires<ExplodesInfo>, Requires<WithFacingSpriteBodyInfo>
 	{
 		[SequenceReference]
 		public readonly string ThumpSequence = "piston";
@@ -87,7 +87,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		}
 	}
 
-	class MadTank : IIssueOrder, IResolveOrder, IOrderVoice, IIssueDeployOrder
+	sealed class MadTank : IIssueOrder, IResolveOrder, IOrderVoice, IIssueDeployOrder
 	{
 		readonly MadTankInfo info;
 
@@ -143,7 +143,7 @@ namespace OpenRA.Mods.Cnc.Traits
 				self.QueueActivity(order.Queued, new DetonationSequence(self, this));
 		}
 
-		class DetonationSequence : Activity
+		sealed class DetonationSequence : Activity
 		{
 			readonly Actor self;
 			readonly MadTank mad;

OpenRA.Mods.Cnc/Traits/Mine.cs

@@ -15,7 +15,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits
 {
-	class MineInfo : TraitInfo
+	sealed class MineInfo : TraitInfo
 	{
 		public readonly BitSet<CrushClass> CrushClasses = default;
 		public readonly bool AvoidFriendly = true;
@@ -25,7 +25,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new Mine(this); }
 	}
 
-	class Mine : ICrushable, INotifyCrushed
+	sealed class Mine : ICrushable, INotifyCrushed
 	{
 		readonly MineInfo info;
 
@@ -70,6 +70,6 @@ namespace OpenRA.Mods.Cnc.Traits
 	}
 
 	[Desc("Tag trait for stuff that should not trigger mines.")]
-	class MineImmuneInfo : TraitInfo<MineImmune> { }
-	class MineImmune { }
+	sealed class MineImmuneInfo : TraitInfo<MineImmune> { }
+	sealed class MineImmune { }
 }

OpenRA.Mods.Cnc/Traits/Minelayer.cs

@@ -204,7 +204,7 @@ namespace OpenRA.Mods.Cnc.Traits
 			return Info.TerrainTypes.Contains(terrainType);
 		}
 
-		class MinefieldOrderGenerator : OrderGenerator
+		sealed class MinefieldOrderGenerator : OrderGenerator
 		{
 			readonly List<Actor> minelayers;
 			readonly Minelayer minelayer;
@@ -347,7 +347,7 @@ namespace OpenRA.Mods.Cnc.Traits
 			}
 		}
 
-		class BeginMinefieldOrderTargeter : IOrderTargeter
+		sealed class BeginMinefieldOrderTargeter : IOrderTargeter
 		{
 			public string OrderID => "BeginMinefield";
 			public int OrderPriority => 5;
@@ -377,7 +377,7 @@ namespace OpenRA.Mods.Cnc.Traits
 				return modifiers.HasModifier(TargetModifiers.ForceAttack);
 			}
 
-			public bool IsQueued { get; protected set; }
+			public bool IsQueued { get; private set; }
 		}
 	}
 }

OpenRA.Mods.Cnc/Traits/PaletteEffects/LightPaletteRotator.cs

@@ -17,7 +17,7 @@ namespace OpenRA.Mods.Cnc.Traits
 {
 	[TraitLocation(SystemActors.World | SystemActors.EditorWorld)]
 	[Desc("Palette effect used for blinking \"animations\" on actors.")]
-	class LightPaletteRotatorInfo : TraitInfo
+	sealed class LightPaletteRotatorInfo : TraitInfo
 	{
 		[Desc("Palettes this effect should not apply to.")]
 		public readonly HashSet<string> ExcludePalettes = new();
@@ -34,7 +34,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new LightPaletteRotator(this); }
 	}
 
-	class LightPaletteRotator : ITick, IPaletteModifier
+	sealed class LightPaletteRotator : ITick, IPaletteModifier
 	{
 		readonly LightPaletteRotatorInfo info;
 		float t = 0;

OpenRA.Mods.Cnc/Traits/PortableChrono.cs

@@ -21,7 +21,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits
 {
-	class PortableChronoInfo : PausableConditionalTraitInfo, Requires<IMoveInfo>
+	sealed class PortableChronoInfo : PausableConditionalTraitInfo, Requires<IMoveInfo>
 	{
 		[Desc("Cooldown in ticks until the unit can teleport.")]
 		public readonly int ChargeDelay = 500;
@@ -78,7 +78,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new PortableChrono(init.Self, this); }
 	}
 
-	class PortableChrono : PausableConditionalTrait<PortableChronoInfo>, IIssueOrder, IResolveOrder, ITick, ISelectionBar, IOrderVoice, ISync
+	sealed class PortableChrono : PausableConditionalTrait<PortableChronoInfo>, IIssueOrder, IResolveOrder, ITick, ISelectionBar, IOrderVoice, ISync
 	{
 		readonly IMove move;
 		[Sync]
@@ -177,7 +177,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		}
 	}
 
-	class PortableChronoOrderTargeter : IOrderTargeter
+	sealed class PortableChronoOrderTargeter : IOrderTargeter
 	{
 		readonly string targetCursor;
 
@@ -188,7 +188,7 @@ namespace OpenRA.Mods.Cnc.Traits
 
 		public string OrderID => "PortableChronoTeleport";
 		public int OrderPriority => 5;
-		public bool IsQueued { get; protected set; }
+		public bool IsQueued { get; private set; }
 		public bool TargetOverridesSelection(Actor self, in Target target, List<Actor> actorsAt, CPos xy, TargetModifiers modifiers) { return true; }
 
 		public bool CanTarget(Actor self, in Target target, ref TargetModifiers modifiers, ref string cursor)
@@ -212,7 +212,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		}
 	}
 
-	class PortableChronoOrderGenerator : OrderGenerator
+	sealed class PortableChronoOrderGenerator : OrderGenerator
 	{
 		readonly Actor self;
 		readonly PortableChrono portableChrono;

OpenRA.Mods.Cnc/Traits/Render/WithBuildingBib.cs

@@ -133,5 +133,5 @@ namespace OpenRA.Mods.Cnc.Traits
 		}
 	}
 
-	class HideBibPreviewInit : RuntimeFlagInit { }
+	sealed class HideBibPreviewInit : RuntimeFlagInit { }
 }

OpenRA.Mods.Cnc/Traits/Render/WithDisguisingInfantryBody.cs

@@ -15,12 +15,12 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits.Render
 {
-	class WithDisguisingInfantryBodyInfo : WithInfantryBodyInfo, Requires<DisguiseInfo>
+	sealed class WithDisguisingInfantryBodyInfo : WithInfantryBodyInfo, Requires<DisguiseInfo>
 	{
 		public override object Create(ActorInitializer init) { return new WithDisguisingInfantryBody(init, this); }
 	}
 
-	class WithDisguisingInfantryBody : WithInfantryBody
+	sealed class WithDisguisingInfantryBody : WithInfantryBody
 	{
 		readonly Disguise disguise;
 		readonly RenderSprites rs;

OpenRA.Mods.Cnc/Traits/Render/WithGunboatBody.cs

@@ -18,7 +18,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits.Render
 {
-	class WithGunboatBodyInfo : WithSpriteBodyInfo, Requires<BodyOrientationInfo>, Requires<IFacingInfo>, Requires<TurretedInfo>
+	sealed class WithGunboatBodyInfo : WithSpriteBodyInfo, Requires<BodyOrientationInfo>, Requires<IFacingInfo>, Requires<TurretedInfo>
 	{
 		[Desc("Turreted 'Turret' key to display")]
 		public readonly string Turret = "primary";
@@ -38,7 +38,7 @@ namespace OpenRA.Mods.Cnc.Traits.Render
 		public override object Create(ActorInitializer init) { return new WithGunboatBody(init, this); }
 	}
 
-	class WithGunboatBody : WithSpriteBody, ITick
+	sealed class WithGunboatBody : WithSpriteBody, ITick
 	{
 		readonly WithGunboatBodyInfo info;
 		readonly Animation wake;

OpenRA.Mods.Cnc/Traits/Render/WithSplitAttackPaletteInfantryBody.cs

@@ -16,7 +16,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits.Render
 {
-	class WithSplitAttackPaletteInfantryBodyInfo : WithInfantryBodyInfo
+	sealed class WithSplitAttackPaletteInfantryBodyInfo : WithInfantryBodyInfo
 	{
 		[PaletteReference]
 		[Desc("Palette to use for the split attack rendering.")]
@@ -28,7 +28,7 @@ namespace OpenRA.Mods.Cnc.Traits.Render
 		public override object Create(ActorInitializer init) { return new WithSplitAttackPaletteInfantryBody(init, this); }
 	}
 
-	class WithSplitAttackPaletteInfantryBody : WithInfantryBody
+	sealed class WithSplitAttackPaletteInfantryBody : WithInfantryBody
 	{
 		readonly WithSplitAttackPaletteInfantryBodyInfo info;
 		readonly Animation splitAnimation;

OpenRA.Mods.Cnc/Traits/SupportPowers/AttackOrderPower.cs

@@ -20,7 +20,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits
 {
-	class AttackOrderPowerInfo : SupportPowerInfo, Requires<AttackBaseInfo>
+	sealed class AttackOrderPowerInfo : SupportPowerInfo, Requires<AttackBaseInfo>
 	{
 		[Desc("Range circle color.")]
 		public readonly Color CircleColor = Color.Red;
@@ -37,7 +37,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new AttackOrderPower(init.Self, this); }
 	}
 
-	class AttackOrderPower : SupportPower, INotifyCreated, INotifyBurstComplete
+	sealed class AttackOrderPower : SupportPower, INotifyCreated, INotifyBurstComplete
 	{
 		readonly AttackOrderPowerInfo info;
 		AttackBase attack;

OpenRA.Mods.Cnc/Traits/SupportPowers/ChronoshiftPower.cs

@@ -19,7 +19,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits
 {
-	class ChronoshiftPowerInfo : SupportPowerInfo
+	sealed class ChronoshiftPowerInfo : SupportPowerInfo
 	{
 		[FieldLoader.Require]
 		[Desc("Size of the footprint of the affected area.")]
@@ -63,7 +63,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new ChronoshiftPower(init.Self, this); }
 	}
 
-	class ChronoshiftPower : SupportPower
+	sealed class ChronoshiftPower : SupportPower
 	{
 		readonly char[] footprint;
 		readonly CVec dimensions;
@@ -140,7 +140,7 @@ namespace OpenRA.Mods.Cnc.Traits
 			return true;
 		}
 
-		class SelectChronoshiftTarget : OrderGenerator
+		sealed class SelectChronoshiftTarget : OrderGenerator
 		{
 			readonly ChronoshiftPower power;
 			readonly char[] footprint;
@@ -218,7 +218,7 @@ namespace OpenRA.Mods.Cnc.Traits
 			}
 		}
 
-		class SelectDestination : OrderGenerator
+		sealed class SelectDestination : OrderGenerator
 		{
 			readonly ChronoshiftPower power;
 			readonly CPos sourceLocation;

OpenRA.Mods.Cnc/Traits/SupportPowers/GpsPower.cs

@@ -18,7 +18,7 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[Desc("Requires `GpsWatcher` on the player actor.")]
-	class GpsPowerInfo : SupportPowerInfo
+	sealed class GpsPowerInfo : SupportPowerInfo
 	{
 		[Desc("Delay in ticks between launching and revealing the map.")]
 		public readonly int RevealDelay = 0;
@@ -53,7 +53,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new GpsPower(init.Self, this); }
 	}
 
-	class GpsPower : SupportPower, INotifyKilled, INotifySold, INotifyOwnerChanged, ITick
+	sealed class GpsPower : SupportPower, INotifyKilled, INotifySold, INotifyOwnerChanged, ITick
 	{
 		readonly Actor self;
 		readonly GpsPowerInfo info;

OpenRA.Mods.Cnc/Traits/SupportPowers/IonCannonPower.cs

@@ -18,7 +18,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits
 {
-	class IonCannonPowerInfo : SupportPowerInfo, IRulesetLoaded
+	sealed class IonCannonPowerInfo : SupportPowerInfo, IRulesetLoaded
 	{
 		[ActorReference]
 		[Desc("Actor to spawn when the attack starts")]
@@ -62,7 +62,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		}
 	}
 
-	class IonCannonPower : SupportPower
+	sealed class IonCannonPower : SupportPower
 	{
 		readonly IonCannonPowerInfo info;
 

OpenRA.Mods.Cnc/Traits/World/ShroudPalette.cs

@@ -20,7 +20,7 @@ namespace OpenRA.Mods.Cnc.Traits
 {
 	[TraitLocation(SystemActors.World | SystemActors.EditorWorld)]
 	[Desc("Adds the hard-coded shroud palette to the game")]
-	class ShroudPaletteInfo : TraitInfo
+	sealed class ShroudPaletteInfo : TraitInfo
 	{
 		[PaletteDefinition]
 		[FieldLoader.Require]
@@ -33,7 +33,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new ShroudPalette(this); }
 	}
 
-	class ShroudPalette : ILoadsPalettes, IProvidesAssetBrowserPalettes
+	sealed class ShroudPalette : ILoadsPalettes, IProvidesAssetBrowserPalettes
 	{
 		readonly ShroudPaletteInfo info;
 

OpenRA.Mods.Cnc/Traits/World/TSEditorResourceLayer.cs

@@ -17,7 +17,7 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[TraitLocation(SystemActors.EditorWorld)]
-	class TSEditorResourceLayerInfo : EditorResourceLayerInfo, Requires<EditorActorLayerInfo>
+	sealed class TSEditorResourceLayerInfo : EditorResourceLayerInfo, Requires<EditorActorLayerInfo>
 	{
 		public readonly string VeinType = "Veins";
 
@@ -28,7 +28,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new TSEditorResourceLayer(init.Self, this); }
 	}
 
-	class TSEditorResourceLayer : EditorResourceLayer
+	sealed class TSEditorResourceLayer : EditorResourceLayer
 	{
 		readonly TSEditorResourceLayerInfo info;
 		readonly EditorActorLayer actorLayer;

OpenRA.Mods.Cnc/Traits/World/TSResourceLayer.cs

@@ -19,7 +19,7 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[TraitLocation(SystemActors.World)]
-	class TSResourceLayerInfo : ResourceLayerInfo
+	sealed class TSResourceLayerInfo : ResourceLayerInfo
 	{
 		public readonly string VeinType = "Veins";
 
@@ -30,7 +30,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new TSResourceLayer(init.Self, this); }
 	}
 
-	class TSResourceLayer : ResourceLayer, INotifyActorDisposing
+	sealed class TSResourceLayer : ResourceLayer, INotifyActorDisposing
 	{
 		readonly TSResourceLayerInfo info;
 		readonly HashSet<CPos> veinholeCells = new();

OpenRA.Mods.Cnc/Traits/World/TSShroudPalette.cs

@@ -19,7 +19,7 @@ namespace OpenRA.Mods.Cnc.Traits
 {
 	[TraitLocation(SystemActors.World | SystemActors.EditorWorld)]
 	[Desc("Adds the hard-coded shroud palette to the game")]
-	class TSShroudPaletteInfo : TraitInfo
+	sealed class TSShroudPaletteInfo : TraitInfo
 	{
 		[PaletteDefinition]
 		[FieldLoader.Require]
@@ -29,7 +29,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		public override object Create(ActorInitializer init) { return new TSShroudPalette(this); }
 	}
 
-	class TSShroudPalette : ILoadsPalettes, IProvidesAssetBrowserPalettes
+	sealed class TSShroudPalette : ILoadsPalettes, IProvidesAssetBrowserPalettes
 	{
 		readonly TSShroudPaletteInfo info;
 

OpenRA.Mods.Cnc/UtilityCommands/ConvertPngToShpCommand.cs

@@ -20,7 +20,7 @@ using OpenRA.Primitives;
 
 namespace OpenRA.Mods.Cnc.UtilityCommands
 {
-	class ConvertPngToShpCommand : IUtilityCommand
+	sealed class ConvertPngToShpCommand : IUtilityCommand
 	{
 		string IUtilityCommand.Name => "--shp";
 

OpenRA.Mods.Cnc/UtilityCommands/ImportRedAlertMapCommand.cs

@@ -19,7 +19,7 @@ using OpenRA.Mods.Common.FileFormats;
 
 namespace OpenRA.Mods.Cnc.UtilityCommands
 {
-	class ImportRedAlertMapCommand : ImportGen1MapCommand, IUtilityCommand
+	sealed class ImportRedAlertMapCommand : ImportGen1MapCommand, IUtilityCommand
 	{
 		// TODO: 128x128 is probably not true for "mega maps" from the expansions.
 		public ImportRedAlertMapCommand()

OpenRA.Mods.Cnc/UtilityCommands/ImportTiberianDawnMapCommand.cs

@@ -17,7 +17,7 @@ using OpenRA.Mods.Common.FileFormats;
 
 namespace OpenRA.Mods.Cnc.UtilityCommands
 {
-	class ImportTiberianDawnMapCommand : ImportGen1MapCommand, IUtilityCommand
+	sealed class ImportTiberianDawnMapCommand : ImportGen1MapCommand, IUtilityCommand
 	{
 		// NOTE: 64x64 map size is a C&C95 engine limitation
 		public ImportTiberianDawnMapCommand()

OpenRA.Mods.Cnc/UtilityCommands/ImportTiberianSunMapCommand.cs

@@ -15,7 +15,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.UtilityCommands
 {
-	class ImportTiberianSunMapCommand : ImportGen2MapCommand, IUtilityCommand
+	sealed class ImportTiberianSunMapCommand : ImportGen2MapCommand, IUtilityCommand
 	{
 		string IUtilityCommand.Name => "--import-ts-map";
 

OpenRA.Mods.Cnc/UtilityCommands/LegacyRulesImporter.cs

@@ -17,7 +17,7 @@ using OpenRA.Mods.Common.FileFormats;
 
 namespace OpenRA.Mods.Cnc.UtilityCommands
 {
-	class LegacyRulesImporter : IUtilityCommand
+	sealed class LegacyRulesImporter : IUtilityCommand
 	{
 		bool IUtilityCommand.ValidateArguments(string[] args)
 		{

OpenRA.Mods.Cnc/UtilityCommands/LegacySequenceImporter.cs

@@ -16,7 +16,7 @@ using OpenRA.Mods.Common.FileFormats;
 
 namespace OpenRA.Mods.Cnc.UtilityCommands
 {
-	class ImportLegacySequenceCommand : IUtilityCommand
+	sealed class ImportLegacySequenceCommand : IUtilityCommand
 	{
 		bool IUtilityCommand.ValidateArguments(string[] args)
 		{

OpenRA.Mods.Cnc/UtilityCommands/LegacyTilesetImporter.cs

@@ -18,7 +18,7 @@ using OpenRA.Mods.Common.FileFormats;
 
 namespace OpenRA.Mods.Cnc.UtilityCommands
 {
-	class ImportLegacyTilesetCommand : IUtilityCommand
+	sealed class ImportLegacyTilesetCommand : IUtilityCommand
 	{
 		string IUtilityCommand.Name => "--tileset-import";
 

OpenRA.Mods.Cnc/UtilityCommands/RemapShpCommand.cs

@@ -20,7 +20,7 @@ using OpenRA.Primitives;
 
 namespace OpenRA.Mods.Cnc.UtilityCommands
 {
-	class RemapShpCommand : IUtilityCommand
+	sealed class RemapShpCommand : IUtilityCommand
 	{
 		string IUtilityCommand.Name => "--remap";
 

OpenRA.Mods.Common/Activities/Air/FlyAttack.cs

@@ -212,7 +212,7 @@ namespace OpenRA.Mods.Common.Activities
 		}
 	}
 
-	class FlyAttackRun : Activity
+	sealed class FlyAttackRun : Activity
 	{
 		readonly AttackAircraft attack;
 		readonly WDist exitRange;
@@ -261,7 +261,7 @@ namespace OpenRA.Mods.Common.Activities
 		}
 	}
 
-	class StrafeAttackRun : Activity
+	sealed class StrafeAttackRun : Activity
 	{
 		readonly AttackAircraft attackAircraft;
 		readonly Aircraft aircraft;

OpenRA.Mods.Common/Activities/DeliverUnit.cs

@@ -64,7 +64,7 @@ namespace OpenRA.Mods.Common.Activities
 				yield return new TargetLineNode(destination, targetLineColor.Value);
 		}
 
-		class ReleaseUnit : Activity
+		sealed class ReleaseUnit : Activity
 		{
 			readonly Carryall carryall;
 			readonly BodyOrientation body;

OpenRA.Mods.Common/Activities/Demolish.cs

@@ -17,7 +17,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Activities
 {
-	class Demolish : Enter
+	sealed class Demolish : Enter
 	{
 		readonly int delay;
 		readonly int flashes;

OpenRA.Mods.Common/Activities/DonateCash.cs

@@ -16,7 +16,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Activities
 {
-	class DonateCash : Enter
+	sealed class DonateCash : Enter
 	{
 		readonly int payload;
 		readonly int playerExperience;

OpenRA.Mods.Common/Activities/DonateExperience.cs

@@ -15,7 +15,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Activities
 {
-	class DonateExperience : Enter
+	sealed class DonateExperience : Enter
 	{
 		readonly int level;
 		readonly int playerExperience;

OpenRA.Mods.Common/Activities/InstantRepair.cs

@@ -14,7 +14,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Activities
 {
-	class InstantRepair : Enter
+	sealed class InstantRepair : Enter
 	{
 		readonly InstantlyRepairsInfo info;
 

OpenRA.Mods.Common/Activities/Move/Move.cs

@@ -486,7 +486,7 @@ namespace OpenRA.Mods.Common.Activities
 			}
 		}
 
-		class MoveFirstHalf : MovePart
+		sealed class MoveFirstHalf : MovePart
 		{
 			public MoveFirstHalf(Move move, WPos from, WPos to, WAngle fromFacing, WAngle toFacing,
 				WRot? fromTerrainOrientation, WRot? toTerrainOrientation, int terrainOrientationMargin, int carryoverProgress, bool shouldArc, bool movingOnGroundLayer)
@@ -569,7 +569,7 @@ namespace OpenRA.Mods.Common.Activities
 			}
 		}
 
-		class MoveSecondHalf : MovePart
+		sealed class MoveSecondHalf : MovePart
 		{
 			public MoveSecondHalf(Move move, WPos from, WPos to, WAngle fromFacing, WAngle toFacing,
 				WRot? fromTerrainOrientation, WRot? toTerrainOrientation, int terrainOrientationMargin, int carryoverProgress, bool shouldArc, bool movingOnGroundLayer)

OpenRA.Mods.Common/Activities/PickupUnit.cs

@@ -135,7 +135,7 @@ namespace OpenRA.Mods.Common.Activities
 				yield return new TargetLineNode(Target.FromActor(cargo), targetLineColor.Value);
 		}
 
-		class AttachUnit : Activity
+		sealed class AttachUnit : Activity
 		{
 			readonly Actor cargo;
 			readonly Carryable carryable;

OpenRA.Mods.Common/Activities/RepairBridge.cs

@@ -15,7 +15,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Activities
 {
-	class RepairBridge : Enter
+	sealed class RepairBridge : Enter
 	{
 		readonly EnterBehaviour enterBehaviour;
 		readonly string speechNotification;

OpenRA.Mods.Common/Activities/RideTransport.cs

@@ -15,7 +15,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Activities
 {
-	class RideTransport : Enter
+	sealed class RideTransport : Enter
 	{
 		readonly Passenger passenger;
 

OpenRA.Mods.Common/Activities/Sell.cs

@@ -16,7 +16,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Activities
 {
-	class Sell : Activity
+	sealed class Sell : Activity
 	{
 		readonly IHealth health;
 		readonly SellableInfo sellableInfo;

OpenRA.Mods.Common/Activities/Transform.cs

@@ -162,7 +162,7 @@ namespace OpenRA.Mods.Common.Activities
 		}
 	}
 
-	class IssueOrderAfterTransform : Activity
+	sealed class IssueOrderAfterTransform : Activity
 	{
 		readonly string orderString;
 		readonly Target target;

OpenRA.Mods.Common/ActorInitializer.cs

@@ -83,7 +83,7 @@ namespace OpenRA.Mods.Common
 			: base(value) { }
 	}
 
-	class ActorInitLoader : TypeConverter
+	sealed class ActorInitLoader : TypeConverter
 	{
 		public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
 		{

OpenRA.Mods.Common/EditorBrushes/EditorActorBrush.cs

@@ -77,7 +77,7 @@ namespace OpenRA.Mods.Common.Widgets
 		}
 	}
 
-	class AddActorAction : IEditorAction
+	sealed class AddActorAction : IEditorAction
 	{
 		public string Text { get; private set; }
 

OpenRA.Mods.Common/EditorBrushes/EditorCopyPasteBrush.cs

@@ -174,7 +174,7 @@ namespace OpenRA.Mods.Common.Widgets
 		}
 	}
 
-	class CopyPasteEditorAction : IEditorAction
+	sealed class CopyPasteEditorAction : IEditorAction
 	{
 		[TranslationReference("amount")]
 		const string CopiedTiles = "notification-copied-tiles";
@@ -271,7 +271,7 @@ namespace OpenRA.Mods.Common.Widgets
 		}
 	}
 
-	class UndoCopyPaste
+	sealed class UndoCopyPaste
 	{
 		public CPos Cell { get; }
 		public TerrainTile MapTile { get; }

OpenRA.Mods.Common/EditorBrushes/EditorDefaultBrush.cs

@@ -108,7 +108,7 @@ namespace OpenRA.Mods.Common.Widgets
 		public void Dispose() { }
 	}
 
-	class RemoveActorAction : IEditorAction
+	sealed class RemoveActorAction : IEditorAction
 	{
 		[TranslationReference("name", "id")]
 		const string RemovedActor = "notification-removed-actor";
@@ -143,7 +143,7 @@ namespace OpenRA.Mods.Common.Widgets
 		}
 	}
 
-	class RemoveResourceAction : IEditorAction
+	sealed class RemoveResourceAction : IEditorAction
 	{
 		[TranslationReference("type")]
 		const string RemovedResource = "notification-removed-resource";

OpenRA.Mods.Common/EditorBrushes/EditorResourceBrush.cs

@@ -103,7 +103,7 @@ namespace OpenRA.Mods.Common.Widgets
 		}
 	}
 
-	class AddResourcesEditorAction : IEditorAction
+	sealed class AddResourcesEditorAction : IEditorAction
 	{
 		[TranslationReference("amount", "type")]
 		const string AddedResource = "notification-added-resource";

OpenRA.Mods.Common/EditorBrushes/EditorTileBrush.cs

@@ -153,7 +153,7 @@ namespace OpenRA.Mods.Common.Widgets
 		}
 	}
 
-	class PaintTileEditorAction : IEditorAction
+	sealed class PaintTileEditorAction : IEditorAction
 	{
 		[TranslationReference("id")]
 		const string AddedTile = "notification-added-tile";
@@ -225,7 +225,7 @@ namespace OpenRA.Mods.Common.Widgets
 		}
 	}
 
-	class FloodFillEditorAction : IEditorAction
+	sealed class FloodFillEditorAction : IEditorAction
 	{
 		[TranslationReference("id")]
 		const string FilledTile = "notification-filled-tile";
@@ -363,7 +363,7 @@ namespace OpenRA.Mods.Common.Widgets
 		}
 	}
 
-	class UndoTile
+	sealed class UndoTile
 	{
 		public CPos Cell { get; }
 		public TerrainTile MapTile { get; }

OpenRA.Mods.Common/Effects/FloatingSprite.cs

@@ -15,7 +15,7 @@ using OpenRA.Graphics;
 
 namespace OpenRA.Mods.Common.Effects
 {
-	class FloatingSprite : IEffect, ISpatiallyPartitionable
+	sealed class FloatingSprite : IEffect, ISpatiallyPartitionable
 	{
 		readonly WDist[] speed;
 		readonly WDist[] gravity;

OpenRA.Mods.Common/FileFormats/Blast.cs

@@ -200,7 +200,7 @@ namespace OpenRA.Mods.Common.FileFormats
 		}
 	}
 
-	class BitReader
+	sealed class BitReader
 	{
 		readonly Stream stream;
 		byte bitBuffer = 0;
@@ -242,7 +242,7 @@ namespace OpenRA.Mods.Common.FileFormats
 	 * codes.  Those tables are the number of codes of each length, and the symbols
 	 * sorted by length, retaining their original order within each length.
 	 */
-	class Huffman
+	sealed class Huffman
 	{
 		public short[] Count; // number of symbols of each length
 		public short[] Symbol; // canonically ordered symbols

OpenRA.Mods.Common/FileFormats/InstallShieldCABCompression.cs

@@ -242,7 +242,7 @@ namespace OpenRA.Mods.Common.FileFormats
 			}
 		}
 
-		class CabExtracter
+		sealed class CabExtracter
 		{
 			readonly FileDescriptor file;
 			readonly Dictionary<int, Stream> volumes;

OpenRA.Mods.Common/FileFormats/MSCabCompression.cs

@@ -20,7 +20,7 @@ namespace OpenRA.Mods.Common.FileFormats
 {
 	public sealed class MSCabCompression
 	{
-		class CabFolder
+		sealed class CabFolder
 		{
 			public readonly uint BlockOffset;
 			public readonly ushort BlockCount;
@@ -34,7 +34,7 @@ namespace OpenRA.Mods.Common.FileFormats
 			}
 		}
 
-		class CabFile
+		sealed class CabFile
 		{
 			public readonly string FileName;
 			public readonly uint DecompressedLength;

OpenRA.Mods.Common/Graphics/ModelRenderable.cs

@@ -115,7 +115,7 @@ namespace OpenRA.Mods.Common.Graphics
 			return new FinalizedModelRenderable(wr, this);
 		}
 
-		class FinalizedModelRenderable : IFinalizedRenderable
+		sealed class FinalizedModelRenderable : IFinalizedRenderable
 		{
 			readonly ModelRenderable model;
 			readonly ModelRenderProxy renderProxy;

OpenRA.Mods.Common/Graphics/UIModelRenderable.cs

@@ -70,7 +70,7 @@ namespace OpenRA.Mods.Common.Graphics
 			return new FinalizedUIModelRenderable(wr, this);
 		}
 
-		class FinalizedUIModelRenderable : IFinalizedRenderable
+		sealed class FinalizedUIModelRenderable : IFinalizedRenderable
 		{
 			readonly UIModelRenderable model;
 			readonly ModelRenderProxy renderProxy;

OpenRA.Mods.Common/Lint/CheckAngle.cs

@@ -15,7 +15,7 @@ using OpenRA.Server;
 
 namespace OpenRA.Mods.Common.Lint
 {
-	class CheckAngle : ILintRulesPass, ILintServerMapPass
+	sealed class CheckAngle : ILintRulesPass, ILintServerMapPass
 	{
 		void ILintRulesPass.Run(Action<string> emitError, Action<string> emitWarning, ModData modData, Ruleset rules)
 		{