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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 _extra_stats(self):
 """Adds ``loglr``, ``optimal_snrsq`` and matched filter snrsq in each detector to the default stats."""

        return ['loglr'] + \
               ['{}_optimal_snrsq'.format(det) for det in self._data] + \
               ['{}_matchedfilter_snrsq'.format(det) for det in self._data]