docs: function initClickEvent (tabheader) {
    const box = tabheader.box
  
    box.addEventListener('click', function (evt) {
      let target = evt.target
      if (target.nodeName === 'UL') {
        return
      }
  
      if (target.parentNode.nodeName === 'LI') {
        target = target.parentNode
      }
  
      const floor = target.getAttribute('data-floor')
      /* eslint-disable eqeqeq */
      if (tabheader.data.attr.selectedIndex == floor) {
        // Duplicated clicking, not to trigger select event.
        return
      }
      /* eslint-enable eqeqeq */
  
      fireEvent(target, 'select', { index: floor })
    })
  }