wxPython - ClearFocusedItem() method in wx.TreeCtrl

import wx

class Tree(wx.Panel):

    def __init__(self, parent):
        wx.Panel.__init__(self, parent)

        # create Tree Control in frame
        self.tree = wx.TreeCtrl(self, wx.ID_ANY, wx.DefaultPosition,
                                                 wx.DefaultSize,
                                                 wx.TR_HAS_BUTTONS)

        # Create root for Tree Control
        self.root = self.tree.AddRoot('Root')

        # Add item to root
        item = self.tree.AppendItem(self.root, 'Item')

        # Clear focused item
        self.tree.ClearFocusedItem()

        # expand tree
        self.tree.Expand(self.root)

        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(self.tree, 0, wx.EXPAND)
        self.SetSizer(sizer)

# main root frame for tree control
class rootframe(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, parent = None, title ='TreeCtrl Demo')
        panel = Tree(self)
        self.Show()


if __name__ == '__main__':
    app = wx.App(redirect = False)
    frame = rootframe()
    app.MainLoop()