anchor.diff:    }
   
     /// Updates data with [values] at actual database location.
  +  ///
  +  /// The [values] must be a Dart [Map], [Iterable] or primitive type.
     Future update(values) => handleThenable(jsObject.update(jsify(values)));
   }
   
  
positive.code:       new OnDisconnect.fromJsObject(jsObject.onDisconnect());
  
    /// Pushes provided [value] to the actual location.
    /// If the [value] is not provided, no data is written to the database
    /// but the [ThenableReference] is still returned and can be used for later
    /// operation.
  
negative.code:   ///
    ///     var event = await ref.once("value");
    ///     print(event.snapshot.val()); //prints 4
    ///
    /// The returned value from [transactionUpdate] function must be
    /// a Dart [Map], [Iterable] or primitive type.
    ///
    /// Set [applyLocally] to [false] to not see intermediate states.
    Future<Transaction> transaction(Func1 transactionUpdate,
  