Restore removed replicas to requiredNumberOfInstances
        :return:

def restore_replicas(self) -> None:
        '''
        Restore removed replicas to requiredNumberOfInstances
        :return:
        '''
        self.backup_instances_faulty.clear()
        for inst_id in range(self.node.requiredNumberOfInstances):
            if inst_id not in self.node.replicas.keys():
                self.node.replicas.add_replica(inst_id)