message: Wrapped prefer larget titles in ios 11 check
diff: NVSearchBarView *searchBar = (NVSearchBarView *) [self.view viewWithTag:SEARCH_BAR];
  NVNavigationBarView *navigationBar = (NVNavigationBarView *) [self.view viewWithTag:NAVIGATION_BAR];
  self.definesPresentationContext = true;
  - self.navigationController.navigationBar.prefersLargeTitles = true;
  if (!!searchBar && !navigationBar.hidden)
  {
  if (@available(iOS 11.0, *)) {
  NVNavigationBarView *navigationBar = (NVNavigationBarView *) [self.view viewWithTag:NAVIGATION_BAR];
  [self.navigationController setNavigationBarHidden:navigationBar.hidden];
  if (@available(iOS 11.0, *)) {
  + self.navigationController.navigationBar.prefersLargeTitles = true;
  [self.navigationItem setLargeTitleDisplayMode:navigationBar.largeTitle ? UINavigationItemLargeTitleDisplayModeAlways : UINavigationItemLargeTitleDisplayModeNever];
  }
  }
  