uch that a moving port can
    // be snapped to be coincident with a compatible stationary port,
    // then move all of the parts by that offset.
    moveParts(parts, offset, check) {
      // when moving an actually copied collection of Parts, use the offset that was calculated during the drag
      if (
        this._snapOffset &&
        this.isActive &&
        this.diagram.lastInput.up &&
        parts === this.copiedParts
      ) {
        super.moveParts(parts, this._snapOffset, check);
        this