copyAndResetAttr(proxy, source) {
    this.copyAttr(proxy, source);

    // reset alpha
    const alpha = source.alpha;
    if (alpha !== undefined) {
      proxy.alpha = Utils.floor(source.alpha, 2);
      proxy.alpha = Math.max(proxy.alpha, 0);
      proxy.alpha = Math.min(proxy.alpha, 1);
    }

    // reset x y
    const { x, y } = source;
    const { offsetX, offsetY } = this.parent;
    if (x !== undefined) {
      proxy.x = proxy.x + offsetX;
    }
    if (y !== undefined) {
      proxy.y = proxy.y + offsetY;
    }

    return proxy;
  }
Clone node attributes to proxy objects
@param {object} proxy - the proxy object
@param {object} source - the source object
@private