title: Disable radio buttons after set as buttonset()
body: <p>I have 3 radio buttons</p>
  
  <pre><code>&lt;div id="test"&gt;
  &lt;input type="radio" id="time1" name="radio" value="1" /&gt;&lt;label for="time1"&gt;Test 1&lt;/label&gt;
  &lt;input type="radio" id="time2" name="radio" value="2" /&gt;&lt;label for="time2"&gt;Test 2&lt;/label&gt;
  &lt;input type="radio" id="time3" name="radio" value="3" /&gt;&lt;label for="time3"&gt;Test 3&lt;/label&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>in jquery</p>
  
  <pre><code>$("#test").buttonset();
  </code></pre>
  
  <p><strong>After that</strong>, I want to disable them with (of course, the disabling are placed in an <code>if</code> statement)</p>
  
  <pre><code>$("#test input").attr("disabled", true);  //or
  $("#test input").prop("disabled", true);
  </code></pre>
  
  <p>but it not works, the buttons are still enabled.</p>