check_once_cc_seq_fetch_creds_begin
check_once_cc_seq_fetch_creds_begin(context, ccache, &creds_iterator, CC_NOERROR, "valid params");
check_once_cc_seq_fetch_creds_begin(context, ccache, NULL, CC_BAD_PARM, "NULL out iterator param");
check_once_cc_seq_fetch_creds_begin(context, ccache, &creds_iterator, CC_NO_EXIST, "invalid ccache");
cc_result check_once_cc_seq_fetch_creds_begin(apiCB *context, ccache_p *ccache, ccache_cit **iterator, cc_result expected_err, const char *description);