def METHOD_NAME(
        self,
        ids_of_all_instances,
        instances_registered_with_elb
):
    instance_healths = []
    ids_of_all_instances = set(ids_of_all_instances)
    ids_of_instances_registered_with_elb = set([x['InstanceId'] for x in instances_registered_with_elb])
    for instance_id in list(ids_of_all_instances - ids_of_instances_registered_with_elb):
        instance = dict([('id', instance_id)])
        instance['description'] = 'N/A (Not registered with Load Balancer)'
        instance['state'] = 'n/a'
        ec2_health = ec2.describe_instance(instance_id)
        instance['health'] = ec2_health['State']['Name']
        instance_healths.append(instance)
    return instance_healths