code: public Iterator<String> getComponentFamilies() {
  
          Set<String> empty = Collections.emptySet();
          return empty.iterator();
  
      }
docs: <p class="changed_added_2_0">Return an <code>Iterator</code> over
  the component-family entries supported by this
  <code>RenderKit</code> instance.</p>
  
  <p class="changed_added_2_0">
  The default implementation of this method returns an empty
  <code>Iterator</code>
  </p>
  
  @since 2.0