protected function getAuthenticationObject()
    {
        if ($this->authObject == null) {
            if (strlen($this->login) <= 0 || strlen($this->password) <= 0) {
                throw new NullPointerException("Login or Password is not set.");
            }
            $auth = new Authentication();
            if (! $auth->authenticate()) {
                throw new AuthException("Authentication Problem. Please check Login and Password.");
            }
            
            $this->authObject = $auth;
        }
        
        return $this->authObject;
    }