_selectItem(autocomplete, item = false) {
    if (item === false && !this.isCustomValueAllowed(autocomplete)) {
      // custom input not allowed, restore to value before input was focused
      this.restoreState(autocomplete);
    } else {
      this._updateInputValues(autocomplete, item);
    }

    this.close(autocomplete);
  }
If item = false, tries to select a custom value;
If custom value not allowed restore initial value (previously selected item or input value attribute otherwise)

@param {HTMLElement} autocomplete
@param {HTMLElement|false} item
@private