best.width += max(self._minimumPaneSize, winbest.width)
                 best.height = max(best.height, winbest.height)
             best.width += sashsize * (len(self._windows)-1)
 
         else:
             for win in self._windows:
                 best.width += max(self._minimumPaneSize, winbest.width)
                 best.height = max(best.height, winbest.height)
             best.width += sashsize * (len(self._windows)-1)
 
         else:
             for win in self._windows: