dontDoThis1.m

- (id) initWithViewModel:(MYTwitterLookupViewModel *) viewModel {
    self = [super init];
    if (!self) return nil;
    _viewModel = viewModel;
    return self;
}
- (void) viewDidLoad {
    [super viewDidLoad];
    _goButton.enabled = viewModel.isUsernameValid;
    _goButton.alpha = viewModel.isUsernameValid ? 1 : 0.5;
    // etc
}