cpp object property getter is called too often for local qml var access

class MySingleton : public QObject
{
    Q_OBJECT
    QML_ELEMENT
    QML_SINGLETON
    Q_PROPERTY(QStringList mark READ mark NOTIFY markChanged)

public:
    explicit MySingleton(QObject* parent = nullptr) : QObject(parent) {}

    QStringList mark()
    {
        qDebug() << "** mark is called";
        return { "mark" };
    }

signals:
    void markChanged();
};

// Some comments here
function example()
{
    var p = MySingleton.mark;
    if (p.length > 0) print(p);
}

** mark is called
** mark is called
[mark]