code: function _onKeyDown(e) {
    var keyCode = e.keyCode;
  
    if (keyCode === 13 || keyCode === 32) {
      this.keyDownFlag = true; // if host element does not naturally trigger a click event on spacebar, we can force one to trigger here.
      // careful! if host already triggers click events naturally, we end up with a "double-click".
  
      if (keyCode === 32 && this.options.simulateSpacebarClick === true) {
        this.hostEl.click();
      }
    }
  }
docs: when options.expandOnClick is true, we set a flag if spacebar or enter are pressed the idea being that this flag is set BEFORE the click event