[myRootRef observeAuthEventWithBlock:^(FAuthData *authData) {
    NSLog(@"got an auth event");
}];

Firebase *child = [myRootRef childByAppendingPath:@"child_path"];

[myRootRef authUser:@"dude@thing.com" password:@"pw" withCompletionBlock:^(NSError *error, FAuthData *authData) {

        NSLog(@"authentication 1 success");
        [child removeAllObservers];
        [self doAuth];
    }
}];

got an auth event
got an auth event
authentication 1 success
authentication 2 success