docs: public <CTX> SafeHtml sanitize(
        @Nullable String html,
        @Nullable HtmlChangeListener<CTX> listener, @Nullable CTX context) {
      if (html == null) { return SafeHtml.EMPTY; }
      return UncheckedConversions.safeHtmlFromStringKnownToSatisfyTypeContract(
          f.sanitize(html, listener, context));
    }