Cleaned up Container lock handling

src/pocketmine/tile/Container.php

@@ -27,6 +27,7 @@ use pocketmine\inventory\Inventory;
 
 interface Container{
 	public const TAG_ITEMS = "Items";
+	public const TAG_LOCK = "Lock";
 
 	/**
 	 * @return Inventory
@@ -37,4 +38,13 @@ interface Container{
 	 * @return Inventory
 	 */
 	public function getRealInventory();
+
+	/**
+	 * Returns whether this container can be opened by an item with the given custom name.
+	 *
+	 * @param string $key
+	 *
+	 * @return bool
+	 */
+	public function canOpenWith(string $key) : bool;
 }