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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 time_to_str(timestamp: int) -> str: """ Convert seconds past Epoch to human readable string. """

    datetimestamp = datetime.datetime.fromtimestamp(timestamp)
    return '{:04d}-{:02d}-{:02d}-{:02d}-{:02d}-{:02d}'.format(
            datetimestamp.year, datetimestamp.month, datetimestamp.day,
            datetimestamp.hour, datetimestamp.minute, datetimestamp.second
    )