removed positionmix entirely (now also in collection)

marl_factory_grid/modules/doors/groups.py

@@ -1,16 +1,19 @@
 from typing import Union
 
 from marl_factory_grid.environment.groups.collection import Collection
-from marl_factory_grid.environment.groups.mixins import PositionMixin
 from marl_factory_grid.modules.doors import constants as d
 from marl_factory_grid.modules.doors.entitites import Door
 
 
-class Doors(PositionMixin, Collection):
+class Doors(Collection):
 
     symbol = d.SYMBOL_DOOR
     _entity = Door
 
+    @property
+    def var_has_position(self):
+        return True
+
     def __init__(self, *args, **kwargs):
         super(Doors, self).__init__(*args, can_collide=True, **kwargs)