code: public CmdLineAction onSwitch(Consumer<@NonNull String> action) {
  		SwitchCmdLineAction switchAction = new SwitchCmdLineAction(action);
  
  		this.switchActions.add(switchAction);
  		return switchAction;
  	}
docs: Add a {@linkplain CmdLineAction} for switch argument ({@code e.g. --switch}) processing.
  
  @param action The {@linkplain Consumer} to invoke with the argument string.
  @return The created {@linkplain CmdLineAction}.