public void createSentryParts() {
    CmmnActivity activity = getActivity();
    ensureNotNull("Case execution '" + id + "': has no current activity", "activity", activity);

    List<CmmnSentryDeclaration> sentries = activity.getSentries();

    if (sentries != null && !sentries.isEmpty()) {

      for (CmmnSentryDeclaration sentryDeclaration : sentries) {

        CmmnIfPartDeclaration ifPartDeclaration = sentryDeclaration.getIfPart();
        if (ifPartDeclaration != null) {
          CmmnSentryPart ifPart = createIfPart(sentryDeclaration, ifPartDeclaration);
          addSentryPart(ifPart);
        }

        List<CmmnOnPartDeclaration> onPartDeclarations = sentryDeclaration.getOnParts();

        for (CmmnOnPartDeclaration onPartDeclaration : onPartDeclarations) {
          CmmnSentryPart onPart = createOnPart(sentryDeclaration, onPartDeclaration);
          addSentryPart(onPart);
        }

        List<CmmnVariableOnPartDeclaration> variableOnPartDeclarations =
            sentryDeclaration.getVariableOnParts();
        for (CmmnVariableOnPartDeclaration variableOnPartDeclaration : variableOnPartDeclarations) {
          CmmnSentryPart variableOnPart =
              createVariableOnPart(sentryDeclaration, variableOnPartDeclaration);
          addSentryPart(variableOnPart);
        }
      }
    }
  }
  protected boolean isSentryPartsSatisfied(
      String sentryId, List<? extends CmmnSentryPart> sentryParts) {
    // if part will be evaluated in the end
    CmmnSentryPart ifPart = null;

    if (sentryParts != null && !sentryParts.isEmpty()) {
      for (CmmnSentryPart sentryPart : sentryParts) {

        if (PLAN_ITEM_ON_PART.equals(sentryPart.getType())) {

          if (!sentryPart.isSatisfied()) {
            return false;
          }

        } else if (VARIABLE_ON_PART.equals(sentryPart.getType())) {
          if (!sentryPart.isSatisfied()) {
            return false;
          }
        } else {
            /* IF_PART.equals(sentryPart.getType) == true */

          ifPart = sentryPart;

          // once the ifPart has been satisfied the whole sentry is satisfied
          if (ifPart.isSatisfied()) {
            return true;
          }
        }
      }
    }

    if (ifPart != null) {

      CmmnExecution execution = ifPart.getCaseExecution();
      ensureNotNull("Case execution of sentry '" + ifPart.getSentryId() + "': is null", execution);

      CmmnActivity activity = ifPart.getCaseExecution().getActivity();
      ensureNotNull("Case execution '" + id + "': has no current activity", "activity", activity);

      CmmnSentryDeclaration sentryDeclaration = activity.getSentry(sentryId);
      ensureNotNull(
          "Case execution '" + id + "': has no declaration for sentry '" + sentryId + "'",
          "sentryDeclaration",
          sentryDeclaration);

      CmmnIfPartDeclaration ifPartDeclaration = sentryDeclaration.getIfPart();
      ensureNotNull(
          "Sentry declaration '"
              + sentryId
              + "' has no definied ifPart, but there should be one defined for case execution '"
              + id
              + "'.",
          "ifPartDeclaration",
          ifPartDeclaration);

      Expression condition = ifPartDeclaration.getCondition();
      ensureNotNull(
          "A condition was expected for ifPart of Sentry declaration '"
              + sentryId
              + "' for case execution '"
              + id
              + "'.",
          "condition",
          condition);

      Object result = condition.getValue(this);
      ensureInstanceOf("condition expression returns non-Boolean", "result", result, Boolean.class);

      Boolean booleanResult = (Boolean) result;
      ifPart.setSatisfied(booleanResult);
      return booleanResult;
    }

    // if all onParts are satisfied and there is no
    // ifPart then the whole sentry is satisfied.
    return true;
  }