REQUIRE_SUCCESS(memcached_set(memc, TEST_KEY, INITIAL_VAL, 0, 0));
REQUIRE_RC(MEMCACHED_NOTSTORED, memcached_add(memc, TEST_KEY, REPLACED_VAL, 0, 0));
REQUIRE_SUCCESS(memcached_set(memc, TEST_KEY, INITIAL_VAL, 0, 0));
REQUIRE_RC(MEMCACHED_NOTSTORED, memcached_add(memc, TEST_KEY, REPLACED_VAL, 0, 0));