title: Null in strings of webservice gets received as string.empty
body: <p>I have a web service with a method that receives and object. One of the properties of the object is a string. The default value is string.empty for this property.</p>
  
  <p>Sometimes I do want to set null on that object and send it. But if I do that and inspect the object is received in debug mode I see that an empty string has been received.</p>
  
  <p>I have tried to call the webservice in two ways, both results in the same string.empty value;</p>
  
  <ul>
  <li>by creating an web service call object from a service reference</li>
  <li>by invoking on a web service proxy</li>
  </ul>
  
  <p>Any ideas how to solve this?</p>