cmd "robot_stopped" = \handle -> do
    message <- ask
    if length (mParts message) /= 1
    then invalid handle
    else do
        let idPart = head $ mParts message
        modify . changeRobot idPart $ \r -> r { status = Off }
cmd "robot_stopped" = \handle -> do
    message <- ask
    if length (mParts message) /= 1
    then invalid handle
    else do
        let idPart = head $ mParts message
        modify . changeRobot idPart $ \r -> r { status = Off }
cmd "robot_stopped" = \handle -> do
    message <- ask
    if length (mParts message) /= 1
    then invalid handle
    else do
        let idPart = head $ mParts message
        modify . changeRobot idPart $ \r -> r { status = Off }