    StringOutput<span class="hl opt">.</span><span class="hl kwa">prototype</span><span class="hl opt">.</span>writeln <span class="hl opt">=</span> <span class="hl kwa">function</span><span class="hl opt">(</span>data<span class="hl opt">,</span> indent<span class="hl opt">) {</span>
      <span class="hl kwa">if</span> <span class="hl opt">(</span>indent <span class="hl opt">==</span> <span class="hl kwa">null</span><span class="hl opt">) {</span>
        indent <span class="hl opt">=</span> <span class="