code: func (b *Blob) Decode(o plumbing.EncodedObject) error {
  	if o.Type() != plumbing.BlobObject {
  		return ErrUnsupportedObject
  	}
  
  	b.Hash = o.Hash()
  	b.Size = o.Size()
  	b.obj = o
  
  	return nil
  }
docs: // Decode transforms a plumbing.EncodedObject into a Blob struct.