code: func NewUsage(client docker.Client, config *api.Config) (*Usage, error) {
  	b, err := New(client, config, fs.NewFileSystem(), build.Overrides{})
  	if err != nil {
  		return nil, err
  	}
  	usage := Usage{
  		handler: b,
  		config:  config,
  		garbage: b.garbage,
  	}
  	return &usage, nil
  }
docs: // NewUsage creates a new instance of the default Usage implementation