code: func DescribeInstanceGroup(asg ASG, instanceGroupName string) (InstanceGroupInfo, error) {
  	request := &autoscaling.DescribeAutoScalingGroupsInput{
  		AutoScalingGroupNames: []*string{aws.String(instanceGroupName)},
  	}
  	response, err := asg.DescribeAutoScalingGroups(request)
  	if err != nil {
  		return nil, fmt.Errorf("error listing AWS autoscaling group (%s): %q", instanceGroupName, err)
  	}
  
  	if len(response.AutoScalingGroups) == 0 {
  		return nil, nil
  	}
  	if len(response.AutoScalingGroups) > 1 {
  		klog.Warning("AWS returned multiple autoscaling groups with name ", instanceGroupName)
  	}
  	group := response.AutoScalingGroups[0]
  	return &awsInstanceGroup{group: group}, nil
  }
docs: // DescribeInstanceGroup gets info about the specified instancegroup
  // Exported so it can be used by the e2e tests,
  // which don't want to instantiate a full cloudprovider.