def _walk_through_windows(self):
        """
        Yields (Split, Window) tuples.
        """
        def walk(split):
            for c in split:
                if isinstance(c, (HSplit, VSplit)):
                    for i in walk(c):
                        yield i
                elif isinstance(c, Window):
                    yield split, c

        return walk(self.root)
Yields (Split, Window) tuples.