formatter(v) {
    // The selectedIndex is not yet updated
    const found = Array.from(this._inputNode.options).find(option => option.value === v);
    return found ? found.text : '';
  }
@override FormatMixin - set formattedValue to selected option text
@param {*} v - modelValue: can be an Object, Number, String depending on the
input type(date, number, email etc)
@returns {string} formattedValue