def draw(self, layout, top, level=0):
        """Draw the node and its children to a layout

        Draws this node to the given layout (presumably a TreeTab), starting
        from a y-offset of `top` and at the given level.
        """
        self._children_top = top
        if self.expanded:
            for i in self.children:
                top = i.draw(layout, top, level)
        self._children_bot = top
        return top
Draw the node and its children to a layout

        Draws this node to the given layout (presumably a TreeTab), starting
        from a y-offset of `top` and at the given level.
        
libqtile/layout/tree.py