anchor.diff:  
     group('once', () {
       test('set a value and get', () {
  -      var testRef = f.child('once');
  +      var testRef = fbClient.child('once');
   
         testRef.once('child_added').then(expectAsync((value) {
           var ds = value as DataSnapshot;
  
positive.code:           'email': 'badCredentialTest@example.com',
            'password': 'WRONG'
          };
          return f.createUser(credentials).then((res) {
            expect(res, isNotNull);
  
            expect(f.authWithPassword(badCredentials), throwsA((error) {
              expect(error['code'], 'INVALID_PASSWORD');
              f.removeUser(credentials).then((err) {
                expect(err, null);
              });
              return true;
  
negative.code: 
      group('startAt', () {
        test('startAt starts at beginning when not specified', () async {
          var child = fbClient.child('startAt 1');
  
          var count = 0;
          await Future.doWhile(() {
  