nssList_AddUnique(list, (void *)c);
if (!nssList_Get(list, (void *)c)) { nssCertificate_AddRef(c); nssList_Add(list, (void *)c); }
collect_certs(NSSCertificate *c, void *arg){    nssList *list = (nssList *)arg;    /* Add the cert to the return list */    nssList_AddUnique(list, (void *)c);    return PR_SUCCESS;}