diff --git a/test.py b/test.py
index e7bd247..68bbdff 100644
--- a/test.py
+++ b/test.py
@@ -11,6 +11,8 @@ from pygame import Surface
 from pygame.time import Clock
 
 
+FPS = 24
+
 def main (
 ) -> None:
     pygame.init ()
@@ -56,7 +58,7 @@ class Game:
         for redrawer in sorted (self.redrawers, key = lambda x: x['layer']):
             redrawer['func'] ()
         pygame.display.update ()
-        self.clock.tick (24)
+        self.clock.tick (FPS)
 
 
 class GameObject:
@@ -187,5 +189,14 @@ def get_surfaces_from_video (
     return surfaces
 
 
+def set_chroma_key (
+        surface:    Surface,
+        color:      tuple[int, int, int],
+        tolerance:  int,
+) -> Surface:
+    # ChatGPT o kwakunin suru kutu
+    ...
+
+
 if __name__ == '__main__':
     main ()