Make fields final if possible to ensure immutability

src/main/java/appeng/hooks/CompassManager.java

@@ -11,7 +11,7 @@ import appeng.core.sync.packets.PacketCompassRequest;
 public class CompassManager
 {
 
-	public static CompassManager instance = new CompassManager();
+	public static final CompassManager instance = new CompassManager();
 
 	class CompassRequest
 	{
@@ -48,7 +48,7 @@ public class CompassManager
 
 	}
 
-	HashMap<CompassRequest, CompassResult> requests = new HashMap<CompassRequest, CompassResult>();
+	final HashMap<CompassRequest, CompassResult> requests = new HashMap<CompassRequest, CompassResult>();
 
 	public void postResult(long attunement, int x, int y, int z, CompassResult result)
 	{

src/main/java/appeng/hooks/MeteoriteWorldGen.java

@@ -62,7 +62,7 @@ final public class MeteoriteWorldGen implements IWorldGenerator
 		final int x;
 		final int z;
 		final World w;
-		int depth;
+		final int depth;
 
 		public MeteoriteSpawn(int x, int depth, int z, World w) {
 			this.x = x;

src/main/java/appeng/hooks/TickHandler.java

@@ -58,7 +58,7 @@ public class TickHandler
 	final public static TickHandler instance = new TickHandler();
 
 	final private WeakHashMap<World, Queue<Callable>> callQueue = new WeakHashMap<World, Queue<Callable>>();
-	Queue<Callable> serverQueue = new LinkedList<Callable>();
+	final Queue<Callable> serverQueue = new LinkedList<Callable>();
 
 	final private HandlerRep server = new HandlerRep();
 	final private HandlerRep client = new HandlerRep();
@@ -282,7 +282,7 @@ public class TickHandler
 		// AELog.info( "processQueue Time: " + time + "ms" );
 	}
 
-	Multimap<World, CraftingJob> craftingJobs = LinkedListMultimap.create();
+	final Multimap<World, CraftingJob> craftingJobs = LinkedListMultimap.create();
 
 	public void registerCraftingSimulation(World world, CraftingJob craftingJob)
 	{