code: def closed_by(self, **kwargs):
          
          path = '%s/%s/closed_by' % (self.manager.path, self.get_id())
          return self.manager.gitlab.http_get(path, **kwargs)
docs: List merge requests that will close the issue when merged.
  
          Args:
              **kwargs: Extra options to send to the server (e.g. sudo)
  
          Raises:
              GitlabAuthenticationError: If authentication is not correct
              GitlabGetErrot: If the merge requests could not be retrieved
  
          Returns:
              list: The list of merge requests.