code: def set_input_focus(self, focus, revert_to, time, onerror = None):
          
          request.SetInputFocus(display = self.display,
                                onerror = onerror,
                                revert_to = revert_to,
                                focus = focus,
                                time = time)
docs: Set input focus to focus, which should be a window,
          X.PointerRoot or X.NONE. revert_to specifies where the focus
          reverts to if the focused window becomes not visible, and should
          be X.RevertToParent, RevertToPointerRoot, or RevertToNone. See
          XSetInputFocus(3X11) for details.
  
          There is also a Window.set_input_focus().