check_maps
ret = check_maps(merged12, ARRAY_SIZE(merged12), maps);
ret = check_maps(merged12, ARRAY_SIZE(merged12), maps);
ret = check_maps(merged3, ARRAY_SIZE(merged3), maps);
ret = check_maps(expected_after_split, ARRAY_SIZE(expected_after_split), maps);
ret = check_maps(expected_final, ARRAY_SIZE(expected_final), maps);