If we try to call the powerOn operation again with the same serial number it will fail, since the Running state does not have a transition associated with powerOn coming out of it.
如果我们尝试使用相同的序列号再次调用powerOn操作，则会失败，因为Running状态没有与powerOn关联的传出转换。
The serialNumber is the parameter for the powerOn operation that creates the state machine.
serialNumber 是创建状态机的 powerOn 操作的参数。
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