# File karel/ur_robot.rb, line 100
  def put_beeper
    pause("put_beeper")
    raise RobotNotRunning, " while putting a beeper" if ! @runstate
    if @beepers == Robota::INFINITY
      # nothing
    elsif @beepers < 1
      self.turn_off
      raise NoBeepersInBeeperBag, "(#@street, #@avenue)"
    else
      @beepers -= 1
    end
    Robota::World.place_beepers(@street, @avenue, 1, true)
    changed
    notify_observers(self, PUT_BEEPER_ACTION, state)
    self
  end