private VertexiumUser createFromVertex(Vertex user) {
    if (user == null) {
      return null;
    }
    String[] authorizations = toArray(getAuthorizations(user), String.class);
    SimpleOrmContext simpleOrmContext = getSimpleOrmContext(authorizations);

    LOGGER.debug(
        "Creating user from UserRow. username: %s",
        UserVisalloProperties.USERNAME.getPropertyValue(user));
    return new VertexiumUser(user, simpleOrmContext);
  }
 @Override
 public User findByUsername(String username) {
   username = formatUsername(username);
   Iterable<Vertex> vertices =
       graph
           .query(authorizations)
           .has(UserVisalloProperties.USERNAME.getPropertyName(), username)
           .has(VisalloProperties.CONCEPT_TYPE.getPropertyName(), userConceptId)
           .vertices();
   Vertex userVertex = singleOrDefault(vertices, null);
   if (userVertex == null) {
     return null;
   }
   userVertexCache.put(userVertex.getId(), userVertex);
   return createFromVertex(userVertex);
 }
  @Override
  protected User addUser(
      String username,
      String displayName,
      String emailAddress,
      String password,
      String[] userAuthorizations) {
    username = formatUsername(username);
    displayName = displayName.trim();
    String authorizationsString = StringUtils.join(userAuthorizations, ",");

    byte[] salt = UserPasswordUtil.getSalt();
    byte[] passwordHash = UserPasswordUtil.hashPassword(password, salt);

    String id = GRAPH_USER_ID_PREFIX + graph.getIdGenerator().nextId();
    VertexBuilder userBuilder = graph.prepareVertex(id, VISIBILITY.getVisibility());

    VisalloProperties.CONCEPT_TYPE.setProperty(
        userBuilder, userConceptId, VISIBILITY.getVisibility());
    UserVisalloProperties.USERNAME.setProperty(userBuilder, username, VISIBILITY.getVisibility());
    UserVisalloProperties.DISPLAY_NAME.setProperty(
        userBuilder, displayName, VISIBILITY.getVisibility());
    UserVisalloProperties.CREATE_DATE.setProperty(
        userBuilder, new Date(), VISIBILITY.getVisibility());
    UserVisalloProperties.PASSWORD_SALT.setProperty(userBuilder, salt, VISIBILITY.getVisibility());
    UserVisalloProperties.PASSWORD_HASH.setProperty(
        userBuilder, passwordHash, VISIBILITY.getVisibility());
    UserVisalloProperties.STATUS.setProperty(
        userBuilder, UserStatus.OFFLINE.toString(), VISIBILITY.getVisibility());
    UserVisalloProperties.AUTHORIZATIONS.setProperty(
        userBuilder, authorizationsString, VISIBILITY.getVisibility());
    UserVisalloProperties.PRIVILEGES.setProperty(
        userBuilder, Privilege.toString(getDefaultPrivileges()), VISIBILITY.getVisibility());

    if (emailAddress != null) {
      UserVisalloProperties.EMAIL_ADDRESS.setProperty(
          userBuilder, emailAddress, VISIBILITY.getVisibility());
    }

    User user = createFromVertex(userBuilder.save(this.authorizations));
    graph.flush();

    afterNewUserAdded(user);

    return user;
  }