docs: def remove_state(self, state):
          """
          Remove this conversation from the given state, and potentially
          deactivate the state if no more conversations are in it.
  
          The relation name will be interpolated in the state name, and it is
          recommended that it be included to avoid conflicts with states from
          other relations.  For example::
  
              conversation.remove_state('{relation_name}.state')
  
          If called from a converation handling the relation "foo", this will
          remove the conversation from the "foo.state" state, and, if no more
          conversations are in this the state, will deactivate it.
          """
          state = state.format(relation_name=self.relation_name)
          value = _get_flag_value(state)
          if not value:
              return
          if self.key in value['conversations']:
              value['conversations'].remove(self.key)
          if value['conversations']:
              set_flag(state, value)
          else:
              clear_flag(state)