Fix CA1852

OpenRA.Mods.Common/Traits/Player/AllyRepair.cs

@@ -15,9 +15,9 @@ namespace OpenRA.Mods.Common.Traits
 {
 	[TraitLocation(SystemActors.Player)]
 	[Desc("Attach this to the player actor to allow building repair by team mates.")]
-	class AllyRepairInfo : TraitInfo<AllyRepair> { }
+	sealed class AllyRepairInfo : TraitInfo<AllyRepair> { }
 
-	class AllyRepair : IResolveOrder
+	sealed class AllyRepair : IResolveOrder
 	{
 		public void ResolveOrder(Actor self, Order order)
 		{

OpenRA.Mods.Common/Traits/Player/EnemyWatcher.cs

@@ -18,7 +18,7 @@ namespace OpenRA.Mods.Common.Traits
 	[TraitLocation(SystemActors.Player)]
 	[Desc("Tracks neutral and enemy actors' visibility and notifies the player.",
 		"Attach this to the player actor. The actors to track need the 'AnnounceOnSeen' trait.")]
-	class EnemyWatcherInfo : TraitInfo
+	sealed class EnemyWatcherInfo : TraitInfo
 	{
 		[Desc("Interval in ticks between scanning for enemies.")]
 		public readonly int ScanInterval = 25;
@@ -29,7 +29,7 @@ namespace OpenRA.Mods.Common.Traits
 		public override object Create(ActorInitializer init) { return new EnemyWatcher(this); }
 	}
 
-	class EnemyWatcher : ITick
+	sealed class EnemyWatcher : ITick
 	{
 		readonly EnemyWatcherInfo info;
 		readonly HashSet<Player> discoveredPlayers;

OpenRA.Mods.Common/Traits/Player/TechTree.cs

@@ -114,7 +114,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		public Player Owner { get; }
 
-		class Watcher
+		sealed class Watcher
 		{
 			public readonly string Key;
 			public ITechTreeElement RegisteredBy { get; }