code: protected void createServiceCheckDecisionState(final Flow flow) {
          createDecisionState(flow, CasWebflowConstants.STATE_ID_SERVICE_CHECK,
              "flowScope.service != null",
              CasWebflowConstants.STATE_ID_GENERATE_SERVICE_TICKET,
              CasWebflowConstants.STATE_ID_VIEW_GENERIC_LOGIN_SUCCESS);
      }
docs: Create service check decision state.
  
  @param flow the flow