public CommandProcessingResult addClientIdentifier(final Long clientId, final JsonCommand command) {
this.context.authenticatedUser();
final ClientIdentifierCommand clientIdentifierCommand = this.clientIdentifierCommandFromApiJsonDeserializer
.commandFromApiJson(command.json());
clientIdentifierCommand.validateForCreate();
final String documentKey = clientIdentifierCommand.getDocumentKey();
String documentTypeLabel = null;
Long documentTypeId = null;
try {