问KonvaJS:拆分后如何保持shape在群中的位置和旋转？

EN

    <button id="ungroup">ungroup</button>
    <div id="container"></div>

    const stage = new Konva.Stage({
       container: 'container',
       width: window.innerWidth,
       height: window.innerHeight
    });

    const layer = new Konva.Layer();
    stage.add(layer);

    const rect = new Konva.Rect({
       x : 50, y : 50, width: 100, height: 100,
       fill: 'black',
    });
    const rect2 = new Konva.Rect({
       x : 150, y : 50, width: 80, height: 80,
       fill: 'red',
    });

    const group = new Konva.Group({
        draggable: true
    });
    group.add(rect);
    group.add(rect2);

    const tr = new Konva.Transformer({
        node: group
    });

    layer.add(group);
    layer.add(tr);
    layer.draw();

    document.getElementById('ungroup').addEventListener('click', () => {
        tr.remove()
      // how can keep the moved or rotated properties?
      rect.moveTo(layer);
      rect2.moveTo(layer);
        group.removeChildren();
      group.remove();
      layer.draw();
    });