code: public B aria(String name, String value) {
          String safeName = name.startsWith("aria-") ? name : "aria-" + name;
          return attr(safeName, value);
      }
docs: Adds an {@code aria-} attribute to the element.
  
  @param name The name of the aria attribute w/o the {@code aria-} prefix. However it won't be added if it's
  already present.