code: func (s *CommonStorageDB) GetValueHash(namespace, collection string, keyHash []byte) (*statedb.VersionedValue, error) {
  	keyHashStr := string(keyHash)
  	if !s.BytesKeySupported() {
  		keyHashStr = base64.StdEncoding.EncodeToString(keyHash)
  	}
  	return s.GetState(deriveHashedDataNs(namespace, collection), keyHashStr)
  }
docs: // GetValueHash implements corresponding function in interface DB