public override BoundNode VisitIndexerAccess(BoundIndexerAccess node)
        {
            var receiverOpt = node.ReceiverOpt;
            VisitRvalue(receiverOpt);
            CheckPossibleNullReceiver(receiverOpt);

            // PROTOTYPE(NullableReferenceTypes): Update indexer based on inferred receiver type.
            VisitArguments(node, node.Arguments, node.ArgumentRefKindsOpt, node.Indexer, node.ArgsToParamsOpt, node.Expanded);

            _resultType = node.Indexer.Type;
            return null;
        }