public login(username: string, password: string): IPromise<Session> {
        return this.$http.post(`${this.kvCoreAppConfig.authenRoot}credentials?format=json`, {
            provider: 'credentials',
            UserName: username,
            Password: password,
            UseTokenCookie : true
        })
        .then((response: IHttpPromiseCallbackArg<Session>) => {
            return TypedJSON.parse(response.data, Session);
        });
    }