добавлен WorldUnloadedException

flat_world/src/main/java/mc/world/flat/SimpleChunk.java

@@ -47,8 +47,7 @@ public class SimpleChunk implements Chunk {
     @Override
     public World getWorld() {
         if (refWorld.get() == null) {
-            log.error("World unloaded?");
-            return null;
+            throw new WorldUnloadedException();
         } else {
             return refWorld.get();
         }

flat_world/src/main/java/mc/world/flat/SimpleChunkSection.java

@@ -71,6 +71,6 @@ public class SimpleChunkSection implements ChunkSection {
 
     @Override
     public World getWorld() {
-        return null;
+        throw new UnsupportedOperationException();
     }
 }

flat_world/src/main/java/mc/world/flat/WorldUnloadedException.java

@@ -0,0 +1,4 @@
+package mc.world.flat;
+
+public class WorldUnloadedException extends RuntimeException {
+}