public ServerCacheControlBuilder sMaxAge(@Nullable Duration sMaxAge) {
        sMaxAgeSeconds = validateDuration(sMaxAge, "sMaxAge");
        return this;
    }
Enables or disables the {@code "s-maxage"} directive.

@param sMaxAge the value of the directive to enable, or {@code null} to disable.
core/src/main/java/com/linecorp/armeria/common/ServerCacheControlBuilder.java