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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 register_instances(self, instances):
 """ Adds instances to this load balancer. All instances must be in the same region as the load balancer. Adding endpoints that are already registered with the load balancer has no effect. :param list instances: List of instance IDs (strings) that you'd like to add to this load balancer. """

        if isinstance(instances, str) or isinstance(instances, unicode):
            instances = [instances]
        new_instances = self.connection.register_instances(self.name, instances)
        self.instances = new_instances