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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 describe_instance_health(self, load_balancer_name, instances=None):
 """ Get current state of all Instances registered to an Load Balancer. :type load_balancer_name: string :param load_balancer_name: The name of the Load Balancer :type instances: List of strings :param instances: The instance ID's of the EC2 instances to return status for. If not provided, the state of all instances will be returned. :rtype: List of :class:`boto.ec2.elb.instancestate.InstanceState` :return: list of state info for instances in this Load Balancer. """

        params = {'LoadBalancerName' : load_balancer_name}
        if instances:
            self.build_list_params(params, instances,
                                   'Instances.member.%d.InstanceId')
        return self.get_list('DescribeInstanceHealth', params,
                             [('member', InstanceState)])