code: def wait_on_action(self, action_id, _check_output=subprocess.check_output):
          
          data = amulet.actions.get_action_output(action_id, full_output=True)
          return data.get(u"status") == "completed"
docs: Wait for a given action, returning if it completed or not.
  
          action_id a string action uuid
          _check_output parameter is no longer used