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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 group_for_policy(self, policy=None):
 """ Lookup the collective.workspace usergroup corresponding to the given policy :param policy: The value of the policy to lookup, defaults to the current policy :type policy: str """

        if policy is None:
            policy = self.context.participant_policy
        return "%s:%s" % (policy.title(), self.context.UID())