Comments, small bugfixes removed legacy elements

marl_factory_grid/modules/doors/entitites.py

@@ -50,7 +50,6 @@ class Door(Entity):
     def is_open(self):
         return self._state == d.STATE_OPEN
 
-
     @property
     def time_to_close(self):
         return self._time_to_close

marl_factory_grid/modules/doors/groups.py

@@ -18,6 +18,7 @@ class Doors(Collection):
     def tick_doors(self, state):
         results = list()
         for door in self:
+            assert isinstance(door, Door)
             tick_result = door.tick(state)
             if tick_result is not None:
                 results.append(tick_result)
@@ -26,4 +27,5 @@ class Doors(Collection):
 
     def reset(self):
         for door in self:
+            assert isinstance(door, Door)
             door.reset()