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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 _get_filename(self):
 """Return a unique file name."""

        if self._fname is None:
            timestamp = datetime.datetime.now().strftime("%Y%m%d-%H%M%S")
            fname = "%s-%s.log" % (timestamp, abs(id(self)))
            self._fname = os.path.join(self.file_path, fname)
        return self._fname