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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 unique_identities(cls, sh_db):
 """List the unique identities available in SortingHat. :param sh_db: SortingHat database """

        try:
            for unique_identity in api.unique_identities(sh_db):
                yield unique_identity
        except Exception as e:
            logger.debug("Unique identities not returned from SortingHat due to %s", str(e))