an><span class="s1">&#39;A&#39;</span><span class="p">,</span> <span class="s1">&#39;B&#39;</span><span class="p">,</span> <span class="s1">&#39;C&#39;</span><span class="p">],</span> <span class="n">default_value</span><span class="o">=</span><span class="s1">&#39;B&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">param</span> <span class="o">=</span> <span class="n">StringParam</span><span class="p">(</span><span class="n">value</span><span class="o">=</span><span c