Groovy httpBuilder POST XML with Basic Authentication

I am trying to send a POST request to a Restful WS with the request originally being xml and so is the response.

I need to have basic authentication sent as well. At first I was having issues with Classes not being defined and thankfully it took 6 jars to resolve that.

Now I keep getting the following: Caught: groovyx.net.http.HttpResponseException: Bad Request

Sounds like it doesn't like the POST request. I have tried different ways including RESTClient, I have tried to delegate the request in its raw xml format by passing a file or as a string var. I don't fully understand the difference between post or request methods in httpBuilder.

If anyone can help point me in what I did wrong would be very thankful

def http = new HTTPBuilder('http://some_IP:some_Port/')
http.auth.basic('userName','password')
http.post(path:'/path/ToServlet')

http.post(POST,XML)
{

  delegate.contentType="text/xml"
  delegate.headers['Content-Type']="text/xml"
  //delegate.post(getClass().getResource("/query.xml"))
 // body = getClass().getResource("/query.xml")
   body = 
   {
      mkp.xmlDeclaration()

        Request{
          Header{
                     Command('Retrieve')
                     EntityIdentifiers
                     {
                       Identifier(Value:'PhoneNumber', Type:'TelephoneNumber')
                      }
                                  EntityName('Subscriber')
                  }
         }
   }
}

Now in case I translated the XML wrong in my request here is the XML version of it:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Provisioning xmlns:xsi="http://ift.tt/ra1lAU">
<Request>
    <Header>
        <Command>Retrieve</Command>
        <EntityIdentifiers>
            <Identifier Value="phoneNumber" Type="TelephoneNumber" />
        </EntityIdentifiers>
        <EntityName>Subscriber</EntityName>
    </Header>
</Request>
</Provisioning>