def _maximize_main(self):
        "Toggle the main pane between min and max size"
        if self.ratio <= 0.5 * (self.max_ratio + self.min_ratio):
            self.ratio = self.max_ratio
        else:
            self.ratio = self.min_ratio
        self.group.layout_all()
Toggle the main pane between min and max size
libqtile/layout/xmonad.py