Merge pull request #3810 from markkrueg/markkrueg-patch-1

Fix Stair.php : add "use pocketmine\item\Tool;"

src/pocketmine/block/Stair.php

@@ -22,6 +22,7 @@
 namespace pocketmine\block;
 
 use pocketmine\item\Item;
+use pocketmine\item\Tool;
 use pocketmine\math\AxisAlignedBB;
 use pocketmine\Player;
 
@@ -151,4 +152,4 @@ abstract class Stair extends Transparent{
 			return [];
 		}
 	}
-}
+}