code: public I run(RunnableWithException runnable) {
          try {
              runnable.run();
          } catch (Exception e) {
              sneakyThrow(e);
          }
          return getThis();
      }
docs: Run some method
  @param runnable Runnable method which sneaks any checked exception
  https://www.baeldung.com/java-sneaky-throws
  Usage:
  SitemapIndexGenerator.of(homepage)
  .run(() -&gt; methodToCall())
  .addPage(WebPage.of("test))
  .toString()
  @return this