message: Refactored previous navigation item into own method
diff: [self.reactViewController.navigationItem setTitle:self.title];
  }
  if ([changedProps containsObject:@"backTitle"]) {
  - NSInteger crumb = [self.reactViewController.navigationController.viewControllers indexOfObject:self.reactViewController];
  - UIViewController *previousController = crumb > 0 ? [self.reactViewController.navigationController.viewControllers objectAtIndex:crumb - 1] : nil;
  - previousController.navigationItem.backBarButtonItem = nil;
  + UINavigationItem *previousNavigationItem = [self previousNavigationItem];
  + previousNavigationItem.backBarButtonItem = nil;
  if (self.backTitle != nil) {
  - previousController.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:self.backTitle style:UIBarButtonItemStylePlain target:nil action:nil];
  + previousNavigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:self.backTitle style:UIBarButtonItemStylePlain target:nil action:nil];
  }
  }
  [self updateStyle];
  if (@available(iOS 11.0, *)) {
  [navigationBar setLargeTitleTextAttributes:largeTitleAttributes];
  }
  - NSInteger crumb = [self.reactViewController.navigationController.viewControllers indexOfObject:self.reactViewController];
  - UIViewController *previousController = crumb > 0 ? [self.reactViewController.navigationController.viewControllers objectAtIndex:crumb - 1] : nil;
  - UIBarButtonItem *backButton;
  + UINavigationItem *previousNavigationItem = [self previousNavigationItem];
  if ([backAttributes objectForKey:NSFontAttributeName]) {
  - NSString *title = self.backTitle ? self.backTitle : previousController.navigationItem.title;
  - backButton = [[UIBarButtonItem alloc] initWithTitle:title style:UIBarButtonItemStylePlain target:nil action:nil];
  - previousController.navigationItem.backBarButtonItem = backButton;
  + NSString *title = self.backTitle ? self.backTitle : previousNavigationItem.title;
  + previousNavigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:title style:UIBarButtonItemStylePlain target:nil action:nil];
  }
  - [backButton setTitleTextAttributes:backAttributes forState:UIControlStateNormal];
  - [backButton setTitleTextAttributes:backAttributes forState:UIControlStateSelected];
  + [previousNavigationItem.backBarButtonItem setTitleTextAttributes:backAttributes forState:UIControlStateNormal];
  + [previousNavigationItem.backBarButtonItem setTitleTextAttributes:backAttributes forState:UIControlStateSelected];
  }
  }
  return attributes;
  }
  +- (UINavigationItem *) previousNavigationItem {
  + NSInteger crumb = [self.reactViewController.navigationController.viewControllers indexOfObject:self.reactViewController];
  + UIViewController *previousController = crumb > 0 ? [self.reactViewController.navigationController.viewControllers objectAtIndex:crumb - 1] : nil;
  + return previousController.navigationItem;
  +}
  +
  - (NSMutableDictionary *) backAttributes
  {
  NSMutableDictionary *attributes = [NSMutableDictionary new];
  