briahas

let asset = NSDataAsset(name: "KanjiDataBase", bundle: Bundle.main)
        // получаем полный путь к каталогу Documents
        // объект класса NSURL
        let urls = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        if let documentUrl = urls.first {
            try! asset?.data.write(to: documentUrl.appendingPathComponent("KanjiDataBase.s3db"), options: [.atomic])
        }

class MyView: UIView {
    let gradient: CALayer 
    ...
    override func layoutSubviews() {
        super.layoutSubviews()
        gradient.frame = self.bounds
    }
}

private var gradientPropertyKey: UInt8 = 0
extension UIView {
    func addNiceGradient() {
        let gradient =  < тут ваш слой >
        layer.addSublayer(gradient)
        let observation = layer.observe(\.bounds) { [weak gradient] layer, _ in
            gradient?.frame = layer.bounds
        }
        objc_setAssociatedObject(self, &gradientPropertyKey, observation, .OBJC_ASSOCIATION_RETAIN)
    }
}

@implementation FIRAuth {
  /** @var _currentUser
      @brief The current user.
   */
  FIRUser *_currentUser;

  /** @var _firebaseAppName
      @brief The Firebase app name.
   */
  NSString *_firebaseAppName;

  /** @var _listenerHandles
      @brief Handles returned from @c NSNotificationCenter for blocks which are "auth state did
          change" notification listeners.
      @remarks Mutations should occur within a @syncronized(self) context.
   */
  NSMutableArray<FIRAuthStateDidChangeListenerHandle> *_listenerHandles;

  /** @var _keychain
      @brief The keychain service.
   */
  FIRAuthKeychain *_keychain;

  /** @var _lastNotifiedUserToken
      @brief The user access (ID) token used last time for posting auth state changed notification.
   */
  NSString *_lastNotifiedUserToken;

  /** @var _autoRefreshTokens
      @brief This flag denotes whether or not tokens should be automatically refreshed.
      @remarks Will only be set to @YES if the another Firebase service is included (additionally to
        Firebase Auth).
   */
  BOOL _autoRefreshTokens;

  /** @var _autoRefreshScheduled
      @brief Whether or not token auto-refresh is currently scheduled.
   */
  BOOL _autoRefreshScheduled;

  /** @var _isAppInBackground
      @brief A flag that is set to YES if the app is put in the background and no when the app is
          returned to the foreground.
   */
  BOOL _isAppInBackground;

  /** @var _applicationDidBecomeActiveObserver
      @brief An opaque object to act as the observer for UIApplicationDidBecomeActiveNotification.
   */
  id<NSObject> _applicationDidBecomeActiveObserver;

  /** @var _applicationDidBecomeActiveObserver
      @brief An opaque object to act as the observer for
          UIApplicationDidEnterBackgroundNotification.
   */
  id<NSObject> _applicationDidEnterBackgroundObserver;
}

class Auth {
 class func auth() -> FIRAuth { ... }
 ...
}

class FIRAuth {
  var currentUser: FIRUser?
  ...
}

class FIRUser {
 var providerData: [Int : {что-то}]
 ...
}

Auth.auth().currentUser?.providerData[indexPath.row]

FUIAuth.defaultAuthUI()?.handleOpen(url, sourceApplication: sourceApplication)

FUIAuth.defaultAuthUI()?.handleOpen(url, sourceApplication: sourceApplication) ?? false

TabelView

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        if (destinationData?[indexPath.row]) != nil {
            if(indexPath.row + 1 >= (destinationData?.count)!) {
                expandCell(tableView: tableView, index: indexPath.row)
            }
            else {
                if(destinationData?[indexPath.row+1] != nil) {
                    expandCell(tableView: tableView, index: indexPath.row)
                    // Close Cell (remove ExpansionCells)
                } else {
                    contractCell(tableView: tableView, index: indexPath.row)
                }
            }
        }
    }
    
    /*  Expand cell at given index  */
    private func expandCell(tableView: UITableView, index: Int) {
        if let infoMain = destinationData?[index]?.infoMain {
            var indexesToInsert = [IndexPath]()
            for i in 1...infoMain.count {
                destinationData?.insert(nil, at: index + 1)
                indexesToInsert.append(IndexPath(row: index + i, section: 0))
            }
            tableView.insertRows(at: indexesToInsert , with: .left)
            tableView.scrollToRow(at: IndexPath(row: index + 1, section: 0), at: .bottom, animated: true)
        }
    }
    
    /*  Contract cell at given index    */
    private func contractCell(tableView: UITableView, index: Int) {
        if let infoMain = destinationData?[index]?.infoMain {
            var indexesToDelete = [IndexPath]()
            for i in 1...infoMain.count {
                destinationData?.remove(at: index + 1)
                indexesToDelete.append(IndexPath(row: index + i, section: 0))
            }
            tableView.deleteRows(at: indexesToDelete, with: .left)
        }
    }

class Time {
    var seconds:Double = 0
    
    init(seconds: Double) {
        self.seconds = seconds
    }
    
    var minutes: Double {
        get {
            return (seconds / 60)
        }
        set {
            self.seconds = (newValue * 60)
        }
    }
    
    var hours: Double {
        get {
            return (seconds / (60 * 60))
        }
        set {
            self.seconds = (newValue * (60 * 60))
        }
    }
    
    var days:  Double {
        get {
            return (seconds / (60 * 60 * 24))
        }
        set {
            self.seconds = (newValue * (60 * 60 * 24))
        }
    }
}