code: def list(self, resource, url_prefix, auth, session, send_opts):
          
  
          req = self.get_metadata_request(
              resource, 'GET', 'application/json', url_prefix, auth)
  
          prep = session.prepare_request(req)
          resp = session.send(prep, **send_opts)
          if resp.status_code == 200:
              keys_dict = resp.json()
              return keys_dict['keys']
  
          err = ('List failed on {}, got HTTP response: ({}) - {}'.format(
              resource.name, resp.status_code, resp.text))
          raise HTTPError(err, request = req, response = resp)
docs: List metadata keys associated with the given resource.
  
          Args:
              resource (intern.resource.boss.BossResource): List keys associated with this resource.
              url_prefix (string): Protocol + host such as https://api.theboss.io
              auth (string): Token to send in the request header.
              session (requests.Session): HTTP session to use for request.
              send_opts (dictionary): Additional arguments to pass to session.send().
  
          Returns:
              (list): List of key names.
  
          Raises:
              requests.HTTPError on failure.