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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 log(self, message, severity=INFO, tag=u""):
 """ Add a given message to the log, and return its time. :param string message: the message to be added :param severity: the severity of the message :type severity: :class:`~aeneas.logger.Logger` :param string tag: the tag associated with the message; usually, the name of the class generating the entry :rtype: datetime """

        entry = _LogEntry(
            severity=severity,
            time=datetime.datetime.now(),
            tag=tag,
            indentation=self.indentation,
            message=self._sanitize(message)
        )
        self.entries.append(entry)
        if self.tee:
            gf.safe_print(entry.pretty_print(show_datetime=self.tee_show_datetime))
        return entry.time