code: def _get_top_level_secrets(self):
          
          top_level_secrets = dict()
          if self.secrets:
              for secret, secret_definition in iteritems(self.secrets):
                  if isinstance(secret_definition, dict):
                      for key, value in iteritems(secret_definition):
                          name = '{}_{}'.format(secret, key)
                          top_level_secrets[name] = dict(external=True)
                  elif isinstance(secret_definition, string_types):
                      top_level_secrets[secret] = dict(external=True)
          return top_level_secrets
docs: Convert the top-level 'secrets' directive to the Docker format
          :return: secrets dict