private ExpressionArea createExpressionArea() {
ExpressionAreaFactory factory = new ExpressionAreaFactory();
factory.setProject(model.getProject());
factory.setTestAction(testAction);
ExpressionArea area = factory.newExpressionArea();
area.getDocument().addDocumentListener(new DocumentContentChangeListener() {
@Override
public void contentChanged(DocumentEvent e) {
updateTestActionStatus();
}