def METHOD_NAME(self) -> list:
    dict_of_keys = {MARKER_KEY: MARKER_INSTRUMENT}
    list_of_dicts = self.mongo_data.get_list_of_result_dicts_for_dict_keys(
        dict_of_keys
    )
    list_of_instruments = [db_entry[INSTRUMENT_KEY] for db_entry in list_of_dicts]
    return list_of_instruments