map_attributes_implementing_interface

function map_attributes_implementing_interface(    interfaces: list<dclass>,     children_mappers: list<(instance, map<text, gtv?>, list<option>) -> unit>,     mapper: (map<text, gtv?>, map<key_name, gtv?>, list<option>) -> unit,     meta: list<meta>?): (instance, map<text, gtv?>, list<option>) -> unit