check_once_cc_context_compare
check_once_cc_context_compare(context_a, context_a, &equal, ccNoError, "valid params, same contexts");
check_once_cc_context_compare(context_a, context_b, &equal, ccNoError, "valid params, different contexts");
check_once_cc_context_compare(context_a, NULL, &equal, ccErrBadParam, "NULL compare_to context");
check_once_cc_context_compare(context_a, context_b, NULL, ccErrBadParam, "NULL out param");
cc_int32 check_once_cc_context_compare(cc_context_t context, cc_context_t compare_to, cc_uint32 *equal, cc_int32 expected_err, const char *description);