code: def search_variant_sets(self, dataset_id):
          
          request = protocol.SearchVariantSetsRequest()
          request.dataset_id = dataset_id
          request.page_size = pb.int(self._page_size)
          return self._run_search_request(
              request, "variantsets", protocol.SearchVariantSetsResponse)
docs: Returns an iterator over the VariantSets fulfilling the specified
          conditions from the specified Dataset.
  
          :param str dataset_id: The ID of the :class:`ga4gh.protocol.Dataset`
              of interest.
          :return: An iterator over the :class:`ga4gh.protocol.VariantSet`
              objects defined by the query parameters.