diff --git a/test.py b/test.py
index a5e578c..75d2759 100644
--- a/test.py
+++ b/test.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from abc import ABCMeta, abstractmethod
+
 import pygame
 
 
@@ -19,13 +21,29 @@ class Game:
         self.clock = pygame.time.Clock ()
 
 
-class Deerjika:
+class GameObject (metaclass = ABCMeta):
+    def __init__ (
+            self,
+            game:   Game,
+    ):
+        self.game = game
+        self.redrawer.append (self.redraw)
+
+    @abstractmethod
+    def redraw (
+            self,
+    ) -> None:
+        raise NotImplementedError ()
+
+
+class Deerjika (GameObject):
     def __init__ (
             self,
             game:       Game,
             pattern:    DeerjikaPattern = DeerjikaPattern.NORMAL,
             direction:  Direction       = Direction.LEFT,
     ):
+        super ().__init__ (self)
         self.game = game
         self.pattern = pattern
         self.direction = direction