diff --git a/tetrislogic/tetromino.py b/tetrislogic/tetromino.py
index 8a57d22..a46411e 100644
--- a/tetrislogic/tetromino.py
+++ b/tetrislogic/tetromino.py
@@ -10,115 +10,114 @@ class Mino:
         self.coord = coord
 
 
+class MetaTetromino(type):
+
+    def __init__(cls, name, bases, dct):
+        super().__init__(name, bases, dct)
+        Tetromino.shapes.append(cls)
+
+
 class Tetromino:
 
+    shapes = []
     random_bag = []
 
-
-    class MetaTetromino(type):
-
-        def __init__(cls, name, bases, dico):
-            super().__init__(name, bases, dico)
-            cls.classes.append(cls)
-
-
-    class AbstractTetromino(list):
-
-        # Super rotation system
-        SRS = {
-            Rotation.CLOCKWISE: (
-                (Coord(0, 0), Coord(-1, 0), Coord(-1, 1), Coord(0, -2), Coord(-1, -2)),
-                (Coord(0, 0), Coord(1, 0), Coord(1, -1), Coord(0, 2), Coord(1, 2)),
-                (Coord(0, 0), Coord(1, 0), Coord(1, 1), Coord(0, -2), Coord(1, -2)),
-                (Coord(0, 0), Coord(-1, 0), Coord(-1, -1), Coord(0, -2), Coord(-1, 2)),
-            ),
-            Rotation.COUNTER: (
-                (Coord(0, 0), Coord(1, 0), Coord(1, 1), Coord(0, -2), Coord(1, -2)),
-                (Coord(0, 0), Coord(1, 0), Coord(1, -1), Coord(0, 2), Coord(1, 2)),
-                (Coord(0, 0), Coord(-1, 0), Coord(-1, 1), Coord(0, -2), Coord(-1, -2)),
-                (Coord(0, 0), Coord(-1, 0), Coord(-1, -1), Coord(0, 2), Coord(-1, 2)),
-            ),
-        }
-        classes = []
-
-        def __init__(self):
-            super().__init__(
-                Mino(self.MINOES_COLOR, coord)
-                for coord in self.MINOES_COORDS
-            )
-            self.orientation = 0
-            self.last_rotation_point = None
-            self.hold_enabled = True
-            self.prelocked = False
-
-        def ghost(self):
-            return self.__class__()
-
-    class O(AbstractTetromino, metaclass=MetaTetromino):
-
-        SRS = {
-            Rotation.CLOCKWISE: (tuple(), tuple(), tuple(), tuple()),
-            Rotation.COUNTER: (tuple(), tuple(), tuple(), tuple()),
-        }
-        MINOES_COORDS = (Coord(0, 0), Coord(1, 0), Coord(0, 1), Coord(1, 1))
-        MINOES_COLOR = "yellow"
-
-        def rotate(self, direction):
-            return False
-
-
-    class I(AbstractTetromino, metaclass=MetaTetromino):
-
-        SRS = {
-            Rotation.CLOCKWISE: (
-                (Coord(1, 0), Coord(-1, 0), Coord(2, 0), Coord(-1, -1), Coord(2, 2)),
-                (Coord(0, -1), Coord(-1, -1), Coord(2, -1), Coord(-1, 1), Coord(2, -2)),
-                (Coord(-1, 0), Coord(1, 0), Coord(-2, 0), Coord(1, 1), Coord(-2, -2)),
-                (Coord(0, -1), Coord(1, 1), Coord(-2, 1), Coord(1, -1), Coord(-2, 2)),
-            ),
-            Rotation.COUNTER: (
-                (Coord(0, -1), Coord(-1, -1), Coord(2, -1), Coord(-1, 1), Coord(2, -2)),
-                (Coord(-1, 0), Coord(1, 0), Coord(-2, 0), Coord(1, 1), Coord(-2, -2)),
-                (Coord(0, 1), Coord(1, 1), Coord(-2, 1), Coord(1, -1), Coord(-2, 2)),
-                (Coord(1, 0), Coord(-1, 0), Coord(2, 0), Coord(-1, -1), Coord(2, 2)),
-            ),
-        }
-        MINOES_COORDS = (Coord(-1, 0), Coord(0, 0), Coord(1, 0), Coord(2, 0))
-        MINOES_COLOR = "cyan"
-
-
-    class T(AbstractTetromino, metaclass=MetaTetromino):
-
-        MINOES_COORDS = (Coord(-1, 0), Coord(0, 0), Coord(0, 1), Coord(1, 0))
-        MINOES_COLOR = "magenta"
-
-
-    class L(AbstractTetromino, metaclass=MetaTetromino):
-
-        MINOES_COORDS = (Coord(-1, 0), Coord(0, 0), Coord(1, 0), Coord(1, 1))
-        MINOES_COLOR = "orange"
-
-
-    class J(AbstractTetromino, metaclass=MetaTetromino):
-
-        MINOES_COORDS = (Coord(-1, 1), Coord(-1, 0), Coord(0, 0), Coord(1, 0))
-        MINOES_COLOR = "blue"
-
-
-    class S(AbstractTetromino, metaclass=MetaTetromino):
-
-        MINOES_COORDS = (Coord(-1, 0), Coord(0, 0), Coord(0, 1), Coord(1, 1))
-        MINOES_COLOR = "green"
-
-
-    class Z(AbstractTetromino, metaclass=MetaTetromino):
-
-        MINOES_COORDS = (Coord(-1, 1), Coord(0, 1), Coord(0, 0), Coord(1, 0))
-        MINOES_COLOR = "red"
-
-
     def __new__(cls):
         if not cls.random_bag:
-            cls.random_bag = list(Tetromino.AbstractTetromino.classes)
+            cls.random_bag = list(cls.shapes)
             random.shuffle(cls.random_bag)
-        return cls.random_bag.pop()()
\ No newline at end of file
+        return cls.random_bag.pop()()
+
+
+class AbstractTetromino(list):
+
+    # Super rotation system
+    SRS = {
+        Rotation.CLOCKWISE: (
+            (Coord(0, 0), Coord(-1, 0), Coord(-1, 1), Coord(0, -2), Coord(-1, -2)),
+            (Coord(0, 0), Coord(1, 0), Coord(1, -1), Coord(0, 2), Coord(1, 2)),
+            (Coord(0, 0), Coord(1, 0), Coord(1, 1), Coord(0, -2), Coord(1, -2)),
+            (Coord(0, 0), Coord(-1, 0), Coord(-1, -1), Coord(0, -2), Coord(-1, 2)),
+        ),
+        Rotation.COUNTER: (
+            (Coord(0, 0), Coord(1, 0), Coord(1, 1), Coord(0, -2), Coord(1, -2)),
+            (Coord(0, 0), Coord(1, 0), Coord(1, -1), Coord(0, 2), Coord(1, 2)),
+            (Coord(0, 0), Coord(-1, 0), Coord(-1, 1), Coord(0, -2), Coord(-1, -2)),
+            (Coord(0, 0), Coord(-1, 0), Coord(-1, -1), Coord(0, 2), Coord(-1, 2)),
+        ),
+    }
+
+    def __init__(self):
+        super().__init__(
+            Mino(self.MINOES_COLOR, coord)
+            for coord in self.MINOES_COORDS
+        )
+        self.orientation = 0
+        self.last_rotation_point = None
+        self.hold_enabled = True
+        self.prelocked = False
+
+    def ghost(self):
+        return self.__class__()
+
+class O(AbstractTetromino, metaclass=MetaTetromino):
+
+    SRS = {
+        Rotation.CLOCKWISE: (tuple(), tuple(), tuple(), tuple()),
+        Rotation.COUNTER: (tuple(), tuple(), tuple(), tuple()),
+    }
+    MINOES_COORDS = (Coord(0, 0), Coord(1, 0), Coord(0, 1), Coord(1, 1))
+    MINOES_COLOR = "yellow"
+
+    def rotate(self, direction):
+        return False
+
+
+class I(AbstractTetromino, metaclass=MetaTetromino):
+
+    SRS = {
+        Rotation.CLOCKWISE: (
+            (Coord(1, 0), Coord(-1, 0), Coord(2, 0), Coord(-1, -1), Coord(2, 2)),
+            (Coord(0, -1), Coord(-1, -1), Coord(2, -1), Coord(-1, 1), Coord(2, -2)),
+            (Coord(-1, 0), Coord(1, 0), Coord(-2, 0), Coord(1, 1), Coord(-2, -2)),
+            (Coord(0, -1), Coord(1, 1), Coord(-2, 1), Coord(1, -1), Coord(-2, 2)),
+        ),
+        Rotation.COUNTER: (
+            (Coord(0, -1), Coord(-1, -1), Coord(2, -1), Coord(-1, 1), Coord(2, -2)),
+            (Coord(-1, 0), Coord(1, 0), Coord(-2, 0), Coord(1, 1), Coord(-2, -2)),
+            (Coord(0, 1), Coord(1, 1), Coord(-2, 1), Coord(1, -1), Coord(-2, 2)),
+            (Coord(1, 0), Coord(-1, 0), Coord(2, 0), Coord(-1, -1), Coord(2, 2)),
+        ),
+    }
+    MINOES_COORDS = (Coord(-1, 0), Coord(0, 0), Coord(1, 0), Coord(2, 0))
+    MINOES_COLOR = "cyan"
+
+
+class T(AbstractTetromino, metaclass=MetaTetromino):
+
+    MINOES_COORDS = (Coord(-1, 0), Coord(0, 0), Coord(0, 1), Coord(1, 0))
+    MINOES_COLOR = "magenta"
+
+
+class L(AbstractTetromino, metaclass=MetaTetromino):
+
+    MINOES_COORDS = (Coord(-1, 0), Coord(0, 0), Coord(1, 0), Coord(1, 1))
+    MINOES_COLOR = "orange"
+
+
+class J(AbstractTetromino, metaclass=MetaTetromino):
+
+    MINOES_COORDS = (Coord(-1, 1), Coord(-1, 0), Coord(0, 0), Coord(1, 0))
+    MINOES_COLOR = "blue"
+
+
+class S(AbstractTetromino, metaclass=MetaTetromino):
+
+    MINOES_COORDS = (Coord(-1, 0), Coord(0, 0), Coord(0, 1), Coord(1, 1))
+    MINOES_COLOR = "green"
+
+
+class Z(AbstractTetromino, metaclass=MetaTetromino):
+
+    MINOES_COORDS = (Coord(-1, 1), Coord(0, 1), Coord(0, 0), Coord(1, 0))
+    MINOES_COLOR = "red"
\ No newline at end of file