From af4905ffbb2eef16376fcd010199697b3e384ed5 Mon Sep 17 00:00:00 2001
From: "P.Y. Laligand" <py.laligand@gmail.com>
Date: Fri, 12 May 2017 10:03:18 -0700
Subject: [PATCH] Fixed analysis error. (#10035)

---
 packages/flutter/lib/src/material/expansion_tile.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/flutter/lib/src/material/expansion_tile.dart b/packages/flutter/lib/src/material/expansion_tile.dart
index e288c2d0dd7..b98cd772161 100644
--- a/packages/flutter/lib/src/material/expansion_tile.dart
+++ b/packages/flutter/lib/src/material/expansion_tile.dart
@@ -112,7 +112,7 @@ class _ExpansionTileState extends State<ExpansionTile> with SingleTickerProvider
       if (_isExpanded)
         _controller.forward();
       else
-        _controller.reverse().then((Null value) {
+        _controller.reverse().then<Null>((Null value) {
           setState(() {
             // Rebuild without widget.children.
           });