title: Xml request header with root element in swift
body: <p>I've been trying to make xml request using <code>Alamofire</code>. However, I got <code>&lt;soap:Text xml:lang="en"&gt;Server was unable to process request. ---&gt; Root element is missing.&lt;/soap:Text&gt;</code> error. Actually, this is my first experience about xml request in ios. How can I achieve to make this request without issue. Here is my code;</p>
  
  <pre><code>Alamofire.request(.POST, "http://example.com/WS.asmx?op=AuthenticateUser", parameters: nil, encoding: .PropertyList(.XMLFormat_v1_0, 0), headers: ["Username": "username", "Password": "password" , "AuthenticatedToken" : "123123"])
                      .responsePropertyList { response in 
      let xml = SWXMLHash.parse(response.data!)
                          print(xml) 
  }
  </code></pre>
  
  <p>What am I doing wrong ? Could you help me please ?</p>
  
  <p>Thank you for your answers</p>
  
  <p>Best regards</p>