code: def _toggle_help(history):
      " Display/hide help. "
      help_buffer_control = history.history_layout.help_buffer_control
  
      if history.app.layout.current_control == help_buffer_control:
          history.app.layout.focus_previous()
      else:
          history.app.layout.current_control = help_buffer_controf _toggle_help(history):
      " Display/hide help. "
      help_buffer_control = history.history_layout.help_buffer_control
  
      if history.app.layout.current_control == help_buffer_control:
          history.app.layout.focus_previous()
      else:
          history.app.layout.current_control = help_buffer_control
docs: Display/hide help.