title: JDOM - cloning MULTIPLE elements - The method clone() is undefined for the type List
body: <p>I recently asked question and one member helped me a lot  how to clone some element and to remove elements from only one element. But same methods are not able to use when there are multiple elements in input XML (this is not duplicate question). On example if I have input XML in this format(of course number of elements is always different):</p>
  
  <pre><code>&lt;SyncMXAUTHCI&gt;
    &lt;MXAUTHCISet&gt;
      &lt;CI&gt;
        &lt;CINAME&gt;COMPUTER68&lt;/CINAME&gt;
      &lt;/CI&gt;
    &lt;/MXAUTHCISet&gt;
  &lt;/SyncMXAUTHCI&gt;
  </code></pre>
  
  <p>and whant to have its clone</p>
  
  <pre><code>&lt;SyncMXAUTHCI&gt;
    &lt;MXAUTHCISet&gt;
      &lt;CI&gt;
        &lt;CINAME&gt;COMPUTER68&lt;/CINAME&gt;
      &lt;/CI&gt;
      &lt;CI&gt;
        &lt;CINAME&gt;COMPUTER68&lt;/CINAME&gt;
      &lt;/CI&gt;
    &lt;/MXAUTHCISet&gt;
  &lt;/SyncMXAUTHCI&gt;
  </code></pre>
  
  <p>I will use this and it works perfectly:</p>
  
  <pre><code>Document erJdom = erData.getData();
  Element root = erJdom.getRootElement();
  Namespace erJdomNamespace = root.getNamespace();
  
  Element incSet = root.getChild("MXAUTHCISet", erJdomNamespace);
  incSet.addContent((Element)incSet.getChild("CI", erJdomNamespace).clone());
  </code></pre>
  
  <p>But what If I have 2 CI elements in input XML:</p>
  
  <pre><code>&lt;SyncMXAUTHCI&gt;
    &lt;MXAUTHCISet&gt;
      &lt;CI&gt;
        &lt;CINAME&gt;COMPUTER68&lt;/CINAME&gt;
      &lt;/CI&gt;
      &lt;CI&gt;
        &lt;CINAME&gt;COMPUTER100&lt;/CINAME&gt;
      &lt;/CI&gt;
    &lt;/MXAUTHCISet&gt;
  &lt;/SyncMXAUTHCI&gt;
  </code></pre>
  
  <p>I tried this with <code>getChildren</code> but it won't compile because:</p>
  
  <pre><code>incSet.addContent((Element)incSet.getChildren("CI", erJdomNamespace).clone());
  </code></pre>
  
  <p>Then it says The method clone() is undefined for the type List</p>
  
  <p>How to clone multiple elements? THANK YOU IN ADVANCE!</p>