code: func (dst *Set) All() []digest.Digest {
  	dst.mutex.RLock()
  	defer dst.mutex.RUnlock()
  	retValues := make([]digest.Digest, len(dst.entries))
  	for i := range dst.entries {
  		retValues[i] = dst.entries[i].digest
  	}
  
  	return retValues
  }
docs: // All returns all the digests in the set