:return: Dict. Should never return None.
        :raise: SolrSwitchedOff
        :raise SolrError: If ...

def retrieve_dataset_handles_or_version_numbers_of_all_versions(self, drs_id, prefix):
        '''
        :return: Dict. Should never return None.
        :raise: SolrSwitchedOff
        :raise SolrError: If ...
        '''
        self.__reset_error_messages()
        response_json = self.__ask_solr_for_handles_or_version_numbers_of_all_versions(drs_id)
        result_dict = self.__parse_result_handles_or_version_numbers_of_all_versions(response_json, prefix)
        return result_dict