'Return the widget which is at the root coordinates ROOTX, ROOTY.'

def winfo_containing(self, rootX, rootY, displayof=0):

    args = ((('winfo', 'containing') + self._displayof(displayof)) + (rootX, rootY))
    name = self.tk.call(args)
    if (not name):
        return None
    else:
        return self._nametowidget(name)
