code: func (ts *tagStore) Get(ctx context.Context, tag string) (distribution.Descriptor, error) {
  	currentPath, err := pathFor(manifestTagCurrentPathSpec{
  		name: ts.repository.Named().Name(),
  		tag:  tag,
  	})
  
  	if err != nil {
  		return distribution.Descriptor{}, err
  	}
  
  	revision, err := ts.blobStore.readlink(ctx, currentPath)
  	if err != nil {
  		switch err.(type) {
  		case storagedriver.PathNotFoundError:
  			return distribution.Descriptor{}, distribution.ErrTagUnknown{Tag: tag}
  		}
  
  		return distribution.Descriptor{}, err
  	}
  
  	return distribution.Descriptor{Digest: revision}, nil
  }
docs: // resolve the current revision for name and tag.