(self, args)
PEN: switch on/off light pen event handling.
PEN: switch on/off light pen event handling.
PEN : switch on / off light pen event handling .
def pen_(self, args):
        """PEN: switch on/off light pen event handling."""
        command, = args
        self.command(self.pen, command)
def pen_ ( self , args ) : command , = args self . command ( self . pen , command )