rem: return (a.node != b.node) || (a.port != b.port) || (a.kind != b.kind);
add: return (a.port != b.port) || (a.id != b.id);
context: bool operator!=(const media_node & a, const media_node & b){	CALLED();	return (a.node != b.node) || (a.port != b.port) || (a.kind != b.kind);}