Addressed comments from review https://codereview.chromium.org/226263007

pkg/shelf/test/request_test.dart

Index: pkg/shelf/test/request_test.dart
diff --git a/pkg/shelf/test/request_test.dart b/pkg/shelf/test/request_test.dart
index 72a87a6b32675f02ea1ae0b32923792a95691bf1..a6235e0b3dc45f12530745d5aa52668ba6d58098 100644
--- a/pkg/shelf/test/request_test.dart
+++ b/pkg/shelf/test/request_test.dart
@@ -11,8 +11,10 @@ import 'package:unittest/unittest.dart';
 
 import 'test_util.dart';
 
-Request _request([Map<String, String> headers, Stream<List<int>> body]) {
-  return new Request("GET", LOCALHOST_URI, headers: headers, body: body);
+Request _request([Map<String, String> headers, Stream<List<int>> body,
+                  Map<String, Object> context]) {
+  return new Request("GET", LOCALHOST_URI, headers: headers, body: body,
+      context: context);
 }
 
 void main() {
@@ -178,4 +180,14 @@ void main() {
       });
     });
   });
+
+  group("context", () {
+    test("is correctly populated", () {
+      expect(_request({
+          'content-type': 'text/plain'
+      }, null, {
+          'my-param' : 42
+      }).context['my-param'], equals(42));
+    });
+  });
 }