code: def remove_members(self, to_remove):
          
  
          if isinstance(to_remove, string_types) or \
                  hasattr(to_remove, "id"):
              warn("need to pass in a list")
              to_remove = [to_remove]
  
          self._members.difference_update(to_remove)
docs: Remove objects from the group.
  
          Parameters
          ----------
          to_remove : list
              A list of cobra objects to remove from the group