title: Add SoapHeader to org.springframework.ws.WebServiceMessage
body: <p>How can I add an object into the soap header of a <code>org.springframework.ws.WebServiceMessage</code></p>
  
  <p>This is the structure I'm looking to end up with:</p>
  
  <pre><code> &lt;soap:Header&gt;
      &lt;credentials xmlns="http://example.com/auth"&gt;
        &lt;username&gt;username&lt;/username&gt;
        &lt;password&gt;password&lt;/password&gt;
      &lt;/credentials&gt;
    &lt;/soap:Header&gt;
  </code></pre>