code: public ServiceFuture<KeyOperationResult> signAsync(String keyIdentifier, JsonWebKeySignatureAlgorithm algorithm,
              byte[] value, final ServiceCallback<KeyOperationResult> serviceCallback) {
          KeyIdentifier id = new KeyIdentifier(keyIdentifier);
          return signAsync(id.vault(), id.name(), id.version() == null ? "" : id.version(), algorithm, value,
                  serviceCallback);
      }
docs: Creates a signature from a digest using the specified key.
  
  @param keyIdentifier
  The full key identifier
  @param algorithm
  algorithm identifier
  @param value
  the content to be signed
  @param serviceCallback
  the async ServiceCallback to handle successful and failed
  responses.
  @return the {@link ServiceFuture} object