public ClientCacheControlBuilder maxStale(@Nullable Duration maxStale) {
        maxStaleSeconds = validateDuration(maxStale, "maxStale");
        return this;
    }
Enables or disables the {@code "max-stale"} directive.

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