code: def get_revision(cls, id, revision, api=None):
          
          api = api if api else cls._API
          extra = {'resource': cls.__name__, 'query': {
              'id': id,
              'revision': revision
          }}
          logger.info('Get revision', extra=extra)
          app = api.get(url=cls._URL['get_revision'].format(
              id=id, revision=revision)).json()
          return App(api=api, **app)
docs: Get app revision.
          :param id: App identifier.
          :param revision: App revision
          :param api: Api instance.
          :return: App object.