@Test
public void shouldSetQuestionGroupInstanceDetailsInSession() throws PageExpiredException {

    List<QuestionGroupInstanceDetail> instanceDetails = asList(getQuestionGroupInstanceDetail("QG1"), getQuestionGroupInstanceDetail("QG2"));
    when(questionnaireServiceFacade.getQuestionGroupInstances(101, "View", "Center")).thenReturn(instanceDetails);
    when(request.getAttribute(Constants.CURRENTFLOWKEY)).thenReturn(FLOW_KEY);
    when(request.getSession()).thenReturn(session);
    when(session.getAttribute(Constants.FLOWMANAGER)).thenReturn(flowManager);
    Flow flow = new Flow();
    when(flowManager.getFlowWithValidation(FLOW_KEY)).thenReturn(flow);
    centerCustAction.setQuestionGroupInstances(questionnaireServiceFacade, request, 101);
    assertThat((List<QuestionGroupInstanceDetail>) flow.getObjectFromSession("questionGroupInstances"), is(instanceDetails));
    verify(questionnaireServiceFacade, times(1)).getQuestionGroupInstances(101, "View", "Center");
    verify(request, times(1)).getAttribute(Constants.CURRENTFLOWKEY);
    verify(request, times(1)).getSession();
    verify(session, times(1)).getAttribute(Constants.FLOWMANAGER);
}