code: func (bh *blobHandler) GetBlob(w http.ResponseWriter, r *http.Request) {
  	context.GetLogger(bh).Debug("GetBlob")
  	blobs := bh.Repository.Blobs(bh)
  	desc, err := blobs.Stat(bh, bh.Digest)
  	if err != nil {
  		if err == distribution.ErrBlobUnknown {
  			bh.Errors = append(bh.Errors, v2.ErrorCodeBlobUnknown.WithDetail(bh.Digest))
  		} else {
  			bh.Errors = append(bh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
  		}
  		return
  	}
  
  	if err := blobs.ServeBlob(bh, w, r, desc.Digest); err != nil {
  		context.GetLogger(bh).Debugf("unexpected error getting blob HTTP handler: %v", err)
  		bh.Errors = append(bh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
  		return
  	}
  }
docs: // GetBlob fetches the binary data from backend storage returns it in the
  // response.