docs: def scroll_window(self, lines):
          u'''Scroll the window by the indicated number of lines.'''
          info = CONSOLE_SCREEN_BUFFER_INFO()
          self.GetConsoleScreenBufferInfo(self.hout, byref(info))
          rect = info.srWindow
          log(u'sw: rtop=%d rbot=%d' % (rect.Top, rect.Bottom))
          top = rect.Top + lines
          bot = rect.Bottom + lines
          h = bot - top
          maxbot = info.dwSize.Y-1
          if top < 0:
              top = 0
              bot = h
          if bot > maxbot:
              bot = maxbot
              top = bot - h
  
          nrect = SMALL_RECT()
          nrect.Top = top
          nrect.Bottom = bot
          nrect.Left = rect.Left
          nrect.Right = rect.Right
          log(u'sn: top=%d bot=%d' % (top, bot))
          r=self.SetConsoleWindowInfo(self.hout, True, byref(nrect))
          log(u'r=%d' % r)