code: def list(self, service_name, **params):
          
          result = self._invoke_call(service_name, 'list', **params)
          if result is not None:
              return result.get(service_name, list())
          return list()
docs: convinent access method for list.
  
          service_name describes the endpoint to call
          the `list` function on.
  
          images.list or apks.list.