updatePassword(email, currentPassword, password): Promise<Auth> {

    return this.apiService.updateVisitorPassword(email, currentPassword, password).then(
      (authData) => {
        return this.authDataPersistenceService.save(authData);
      }
    );
  }

 signIn(email: string, password: string): Promise<Auth|AuthError> {
   return this.apiService.login(email, password)
   .then((response: Auth) => {
     console.log('AuthService, signIn succeed');
     if (response.error === 'password expired') {
       this.authDataPersistenceService.set(response);
       return Promise.reject({message: 'passwordExpired'});
     } else {
       return this.authDataPersistenceService.save(response);
     }
   });
 }

 fetchByCategory(id: number): Promise<Item[]> {
   return this.apiService.fetchItemsByCategory(id);
 }

 fetchAll(): Promise<Item[]> {
   return this.apiService.fetchLatestItems();
 }

 fetchById(id: string): Promise<Item> {
   return this.apiService.fetchItemById(id);
 }

 forgotPassword(email: string): Promise<void> {
   return this.apiService.forgotPassword(email);
 }