code: @Override
      public void renderLoop( PositionedText target, double x, double y, Size size, Diagram.Figure forward,
                              Diagram.Figure backward, String description, boolean forwardDirection )
      {
          throw new UnsupportedOperationException( "not implemented" );
      }
docs: <b>Example:</b>
  <pre><code>
  +--|two|&lt;-+
  |         |
  o-+-&gt;|one|--+-&gt;o
  </code></pre>