# File karel/ur_robot.rb, line 82
  def pick_beeper
    pause("pick_beeper")
    raise RobotNotRunning, " while picking a beeper" if ! @runstate
    if Robota::World.beepers_at?(@street, @avenue)
      if @beepers != Robota::INFINITY
        @beepers += 1      
      end
      Robota::World.remove_beeper(@street, @avenue)
    else
      self.turn_off
      raise NoBeepers,  "(#@street, #@avenue)"
    end
    changed
    notify_observers(self, PICK_BEEPER_ACTION, state)
    self
  end