code: def previous_layout(pymux, variables):
      " Select previous layout. "
      pane = pymux.arrangement.get_active_window()
      if pane:
          pane.select_previous_layout(f previous_layout(pymux, variables):
      " Select previous layout. "
      pane = pymux.arrangement.get_active_window()
      if pane:
          pane.select_previous_layout()
docs: Select previous layout.