code: def query(cls, visibility=None, api=None):
          
          api = api if api else cls._API
  
          return super(Dataset, cls)._query(
              url=cls._URL['query'],
              visibility=visibility,
              fields='_all', api=api
          )
docs: Query ( List ) datasets
          :param visibility: If provided as 'public', retrieves public datasets
          :param api: Api instance
          :return: Collection object