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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 manage_extant(self, **kwargs):
        '''Manage an existing cluster

        :param kwargs: dict -- keyword args in dict
        '''

        self._check_device_number(kwargs['devices'])
        self.trust_domain = TrustDomain(
            devices=kwargs['devices'],
            partition=kwargs['device_group_partition']
        )
        self.device_group = DeviceGroup(**kwargs)
        self.cluster = Cluster(**kwargs)