code: @Implementation(minSdk = LOLLIPOP)
    @HiddenApi
    public void setRestriction(
        int code, @AttributeUsage int usage, int mode, String[] exceptionPackages) {
      audioRestrictions.put(
          getAudioRestrictionKey(code, usage), new ModeAndException(mode, exceptionPackages));
    }
docs: Sets audio restrictions.
  
  <p>This method is public for testing, as the original method is {@code @hide}.