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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def sagemaker_timestamp():
 """Return a timestamp with millisecond precision."""

    moment = time.time()
    moment_ms = repr(moment).split('.')[1][:3]
    return time.strftime("%Y-%m-%d-%H-%M-%S-{}".format(moment_ms), time.gmtime(moment))