code: @Override
      public void process(Request request, Response response)
      {
  		if (!response.hasHeader(CORRELATION_ID))
  		{
  			response.addHeader(CORRELATION_ID, request.getHeader(CORRELATION_ID));
  		}
      }
docs: Postprocessor method that assigns the Correlation-Id from the
  request to a header on the Response.
  
  @param request the incoming Request.
  @param response the outgoing Response.