static QGraphicsWidget *createItem(const QSizeF &minimum = QSizeF(100.0, 100.0),
                                   const QSizeF &preferred = QSize(150.0, 100.0),
                                   const QSizeF &maximum = QSizeF(200.0, 100.0),
                                   const QString &name = QString())
{
    QGraphicsWidget *w = new RectWidget;
    w->setMinimumSize(minimum);
    w->setPreferredSize(preferred);
    w->setMaximumSize(maximum);
    w->setData(0, name);
    return w;
}