Item: fixed documentation of pop() return type (it's not fluent)

src/pocketmine/item/Item.php

@@ -569,7 +569,7 @@ class Item implements ItemIds, \JsonSerializable{
 	/**
 	 * Pops an item from the stack and returns it, decreasing the stack count of this item stack by one.
 	 *
-	 * @return $this
+	 * @return static A clone of this itemstack containing the amount of items that were removed from this stack.
 	 * @throws \InvalidArgumentException if trying to pop more items than are on the stack
 	 */
 	public function pop(int $count = 1) : Item{