if (className != null) {
caseExecutionListener = new ClassDelegateCaseExecutionListener(className, fieldDeclarations);
} else if (expression != null) {
Expression expressionExp = expressionManager.createExpression(expression);
caseExecutionListener = new ExpressionCaseExecutionListener(expressionExp);
} else if (delegateExpression != null) {
Expression delegateExp = expressionManager.createExpression(delegateExpression);
caseExecutionListener = new DelegateExpressionCaseExecutionListener(delegateExp, fieldDeclarations);