async openPrep () {
    if (this.svgCanvas.undoMgr.getUndoStackSize() === 0) {
      return true
    }
    return await seConfirm(this.i18next.t('notification.QwantToOpen'))
  }
@function module:SVGthis.openPrep
@returns {boolean|Promise<boolean>} Resolves to boolean indicating `true` if there were no changes
 and `false` after the user confirms.