code: def break_pane(self, set_active=True):
          
          w = self.get_active_window()
  
          if len(w.panes) > 1:
              pane = w.active_pane
              self.get_active_window().remove_pane(pane)
              self.create_window(pane, set_active=set_active)
docs: When the current window has multiple panes, remove the pane from this
          window and put it in a new window.
  
          :param set_active: When True, focus the new window.