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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_groups(self, username):
 """ Get groups of a user @str username: name of the user @rtype: dict, format { '<backend>': [<list of groups>] } """

        ret = {}
        for b in self.backends:
            ret[b] = self.backends[b].get_groups(username)
        cherrypy.log.error(
            msg="user '" + username + "' groups: " + str(ret),
            severity=logging.DEBUG,
        )
        return ret