Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/Configuration/AdapterDictionary.cs

@@ -0,0 +1,28 @@
+//------------------------------------------------------------------------------
+// <copyright file="AdapterDictionary.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web.Configuration {
+
+    using System;
+    using System.Collections;
+    using System.Collections.Specialized;
+    using System.Security.Permissions;
+
+    [Serializable]
+    public class AdapterDictionary : OrderedDictionary {
+        public AdapterDictionary() {
+        }
+
+        public string this[string key] {
+            get {
+                return (string)base[key];
+            }
+            set {
+                base[key] = value;
+            }
+        }
+    }
+}