def add_policy_alias(self, policy_index, *aliases):
        """
        Adds a new name or names to a policy

        :param policy_index: index of a policy in this policy collection.
        :param aliases: arbitrary number of string policy names to add.
        """
        policy = self.get_by_index(policy_index)
        for alias in aliases:
            if alias.upper() in self.by_name:
                raise PolicyError('Duplicate name %s in use '
                                  'by policy %s' % (alias,
                                                    self.get_by_name(alias)))
            else:
                policy.add_name(alias)
                self.by_name[alias.upper()] = policy
dataset/ETHPy150Open openstack/swift/swift/common/storage_policy.py/StoragePolicyCollection.add_policy_alias/original