check_once_cc_ccache_get_kdc_time_offset
check_once_cc_ccache_get_kdc_time_offset(ccache, cc_credentials_v5, &time_offset, ccErrTimeOffsetNotSet, "brand new ccache (offset not yet set)");
check_once_cc_ccache_get_kdc_time_offset(ccache, cc_credentials_v5, &time_offset, ccNoError, "offset set for v5");
check_once_cc_ccache_get_kdc_time_offset(ccache, cc_credentials_v5, NULL, ccErrBadParam, "NULL time_offset out param");
cc_int32 check_once_cc_ccache_get_kdc_time_offset(cc_ccache_t ccache, cc_int32 credentials_version, cc_time_t *time_offset, cc_int32 expected_err, const char *description);