anchor.diff:      return null;
     }
   
  -  /// Warning as it does not introduce any context
  -  /// We'll need a transaction context in the other calls
  -  @deprecated
  -  Future<Transaction> beginTransaction({bool exclusive}) async {
  -    Transaction transaction = new Transaction();
  +  Future<_Transaction> _beginTransaction({bool exclusive}) async {
  +    _Transaction transaction = new _Transaction();
       if (exclusive == true) {
         await execute("BEGIN EXCLUSIVE;");
       } else {
  
positive.code:   }
  }
  
  class Transaction {
    bool successfull;
  }
  
  class Database {
    String get path => _path;
    String _path;
    int _id;
    Database._(this._path, this._id);
    var lock = new SynchronizedLock();
  
    @override
    String toString() {
  
negative.code: const String _methodInsert = "insert";
  const String _methodUpdate = "update";
  const String _methodQuery = "query";
  const String _methodGetPlatformVersion = "getPlatformVersion";
  
  const String _channelName = 'com.tekartik.sqflite';
  
  class Sqflite {
    static const MethodChannel _channel =
        const MethodChannel(_channelName);
  
    static Future<String> get platformVersion =>
        _channel.invokeMethod(_methodGetPlatformVersion);
  
    static Future setDebugModeOn([bool on = true]) async {
      await Sqflite._channel.invokeMethod(_methodSetDebugModeOn, on);
    }
  
    static firstIntValue(List<Map> list) {
  