Dragons now throw events when creating portals

src/main/java/org/bukkit/craftbukkit/util/BlockStateListPopulator.java

@@ -0,0 +1,29 @@
+package org.bukkit.craftbukkit.util;
+
+import java.util.List;
+import org.bukkit.World;
+import org.bukkit.block.BlockState;
+
+public class BlockStateListPopulator {
+    private final World world;
+    private final List<BlockState> list;
+
+    public BlockStateListPopulator(World world, List<BlockState> list) {
+        this.world = world;
+        this.list = list;
+    }
+
+    public void setTypeId(int x, int y, int z, int type) {
+        BlockState state = world.getBlockAt(x, y, z).getState();
+        state.setTypeId(type);
+        list.add(state);
+    }
+
+    public List<BlockState> getList() {
+        return list;
+    }
+
+    public World getWorld() {
+        return world;
+    }
+}