code: public void forward(final ExpectationForwardCallback expectationForwardCallback) {
          expectation.thenForward(new HttpObjectCallback().withClientId(registerWebSocketClient(expectationForwardCallback)));
          mockServerClient.sendExpectation(expectation);
      }
docs: Call method on object locally or remotely (over web socket)
  to generate request to forward when expectation is matched
  
  @param expectationForwardCallback object to call locally or remotely to generate request