code: protected ServiceSummary getServiceSummary() throws ActivityException {
          ServiceSummary serviceSummary = (ServiceSummary)getVariableValue("serviceSummary");
          if (serviceSummary == null)
              throw new ActivityException("Missing variable: serviceSummary");
          return serviceSummary;
      }
docs: If you really must name the variable something other than 'serviceSummary',
  you can override this method to retrieve its value.