code: func (p *AWSSDProvider) ListInstancesByServiceID(serviceID *string) ([]*sd.InstanceSummary, error) {
  	instances := make([]*sd.InstanceSummary, 0)
  
  	f := func(resp *sd.ListInstancesOutput, lastPage bool) bool {
  		instances = append(instances, resp.Instances...)
  
  		return true
  	}
  
  	err := p.client.ListInstancesPages(&sd.ListInstancesInput{
  		ServiceId: serviceID,
  	}, f)
  	if err != nil {
  		return nil, err
  	}
  
  	return instances, nil
  }
docs: // ListInstancesByServiceID returns list of instances registered in given service.