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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_enqueued(self):
 """Retrieve the timestamp at which the task was enqueued. See: https://cloud.google.com/appengine/docs/python/taskqueue/rest/tasks :rtype: :class:`datetime.datetime` or ``NoneType`` :returns: Datetime object parsed from microsecond timestamp, or ``None`` if the property is not set locally. """

        value = self._properties.get('enqueueTimestamp')
        if value is not None:
            return _datetime_from_microseconds(int(value))