C5RACAlmostFinalForm.m

RAC(self, 'titleLabel.text') =
  [self.selectedRegion map:^NSString*(WTFRegion *region) {
    return region.title;
}];

RACSignal *regionRect = [self.selectedRegion map:^NSValue*(WTFRegion *region) {
  return [NSValue valueFromMKMapRect:region.rect];
}];
[self.mapView rac_liftSelector:@selector(setVisibleMapRect:animated:)
                   withSignals:regionRect, [RACSignal return:@(YES)], nil];

RACSignal *annotations = [self rac_liftSelector:@selector(fetchAnnotationsForRegion:)
                                    withObjects:selectedRegion, nil];
[self.mapView rac_liftSelector:@selector(addAnnotations:)
                   withSignals:annotations, nil];