title: How do I use WS-Addressing in WCF and set the wsa:replyto header?
body: <p>I'm calling a BizTalk service using WCF. The service requires the wsa:replyto address to be set in the SOAP header to able to make a 'callback' when the process is done.</p>
  
  <p>We are using a contract-first approch with auto-generated code from svcutil (we cannot 'just' change the contract)...</p>
  
  <p>And it's not possible to do in the config file...</p>
  
  <p>I have seen someone 'overriding' some methods to make their own custom header - but this is not a custom header it's a standard in the SOAP protocol.</p>
  
  <p>How can I add the wsa:replyto in the (SOAP) header?</p>