just some refactor, a line is misplaced

grid/ui/items.py

@@ -1,4 +1,5 @@
 import logging
+import random
 
 from PySide6.QtCore import QRectF, Qt
 from PySide6.QtGui import QBrush, QPainter, QPen
@@ -59,6 +60,23 @@ class AgilitySphereGraphicsItem(SphereGraphicsItem):
     def __init__(self, x_pos: int, y_pos: int) -> None:
         super().__init__(x_pos, y_pos, Qt.GlobalColor.darkYellow)
 
+class EmptySphereGraphicsItem(SphereGraphicsItem):
+    def __init__(self, x_pos: int, y_pos: int) -> None:
+        self.SPHERE_WIDTH = 20
+        super().__init__(x_pos, y_pos, Qt.GlobalColor.black)
+
+@staticmethod
+def random_sphere_factory(x_pos: int, y_pos: int) -> SphereGraphicsItem:
+    rand = random.random()
+    if rand > 3 / 4:
+        obj = SphereGraphicsItem(x_pos, y_pos)
+    elif rand > 2 / 4:
+        obj = AgilitySphereGraphicsItem(x_pos, y_pos)
+    elif rand > 1 / 4:
+        obj = StrenghSphereGraphicsItem(x_pos, y_pos)
+    else:
+        obj = EmptySphereGraphicsItem(x_pos, y_pos)
+    return obj
 
 class ArcGraphicsItem(QGraphicsItem):
     """Circle arc."""