# File karel/ur_robot.rb, line 71
  def turn_left
    pause("turn_left")
    raise RobotNotRunning, " while turning left" if ! @runstate
    @direction = @direction.next
    #    Robota::World.register_robot(self, [@street, @avenue, @direction])
    changed
    notify_observers(self, TURN_LEFT_ACTION, state)
    self
  end