Added getHighestBlockYAt

By: FrozenCow <frozencow@gmail.com>

paper-api/src/main/java/org/bukkit/World.java

@@ -20,6 +20,14 @@ public interface World {
      */
     public Block getBlockAt(int x, int y, int z);
 
+    /**
+     * Gets the highest non-air coordinate at the given (x,z) location
+     * @param x X-coordinate of the blocks
+     * @param z Z-coordinate of the blocks
+     * @return Y-coordinate of the highest non-air block
+     */
+    public int getHighestBlockYAt(int x, int z);
+
     /**
      * Gets the chunk at the given location
      *