From 22672f33877b2170c2b2f6edb806ce16d57f66d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=8E=8B=E6=96=87=E7=92=90?= <kingwenlu@gmail.com>
Date: Fri, 7 Sep 2018 11:45:32 +0800
Subject: [PATCH] add comment

---
 src/compiler/visitor.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/compiler/visitor.ts b/src/compiler/visitor.ts
index 9a7c1c41cfd..5fc0b0ccc71 100644
--- a/src/compiler/visitor.ts
+++ b/src/compiler/visitor.ts
@@ -268,6 +268,7 @@ namespace ts {
                     nodesVisitor((<PropertyDeclaration>node).decorators, visitor, isDecorator),
                     nodesVisitor((<PropertyDeclaration>node).modifiers, visitor, isModifier),
                     visitNode((<PropertyDeclaration>node).name, visitor, isPropertyName),
+                    // QuestionToken and ExclamationToken is uniqued in Property Declaration and the signature of 'updateProperty' is that too
                     (visitNode((<PropertyDeclaration>node).questionToken, tokenVisitor, isToken), visitNode((<PropertyDeclaration>node).exclamationToken, tokenVisitor, isToken)),
                     visitNode((<PropertyDeclaration>node).type, visitor, isTypeNode),
                     visitNode((<PropertyDeclaration>node).initializer, visitor, isExpression));