     if element.tagName == 'OL' and element.classList.contains 'children'
       element = element.parentElement
 
-    if element == @_treeRoot
+    if element == @treeRoot
       element = element.lastChild
       element = element.previousSibling if element.tagName == 'OL'
       return { target: element, where: 'below' }
 
     while element.tagName != 'LI' or (! element.classList.contains('item') and ! element.classList.contains('group'))
-      return null if element == @_treeRoot
+      return null if element == @treeRoot
       element = element.parentElement
 
     where = @_getInsertionPoint element, event.pageY


    element = event.target
    while element.tagName != 'LI' or (! element.classList.contains('item') and ! element.classList.contains('group'))
      return selectionChanged if element == @_treeRoot
      element = element.parentElement

    if @selectedNodes.length > 0 and @selectedNodes[0].parentElement != element.parentElement

    event.preventDefault()

  _clearDropClasses: ->
    @treeRoot.querySelector('.drop-above')?.classList.remove('drop-above')
    @treeRoot.querySelector('.drop-inside')?.classList.remove('drop-inside')
    @treeRoot.querySelector('.drop-below')?.classList.remove('drop-below')
    return

  _onDragLeave: (event) =>
