code: func NewManifestBuilder(bs distribution.BlobService, configMediaType string, configJSON []byte) distribution.ManifestBuilder {
  	mb := &builder{
  		bs:              bs,
  		configMediaType: configMediaType,
  		configJSON:      make([]byte, len(configJSON)),
  	}
  	copy(mb.configJSON, configJSON)
  
  	return mb
  }
docs: // NewManifestBuilder is used to build new manifests for the current schema
  // version. It takes a BlobService so it can publish the configuration blob
  // as part of the Build process.