getRange(cfiRange) {
    var cfi = new epubcfi["a" /* default */](cfiRange);
    var item = this.spine.get(cfi.spinePos);

    var _request = this.load.bind(this);

    if (!item) {
      return new Promise((resolve, reject) => {
        reject("CFI could not be found");
      });
    }

    return item.load(_request).then(function (contents) {
      var range = cfi.toRange(item.document);
      return range;
    });
  }
Find a DOM Range for a given CFI Range
@param  {EpubCFI} cfiRange a epub cfi range
@return {Range}