Use default state a bit more.

worldedit-core/src/main/java/com/sk89q/worldedit/world/AbstractWorld.java

@@ -94,7 +94,7 @@ public abstract class AbstractWorld implements World {
         }
 
         try {
-            setBlock(pt, new BaseBlock(BlockTypes.AIR));
+            setBlock(pt, BlockTypes.AIR.getDefaultState());
         } catch (WorldEditException e) {
             throw new RuntimeException(e);
         }