diff --git a/src/ProtocolBuffers.Test/ExtendableMessageTest.cs b/src/ProtocolBuffers.Test/ExtendableMessageTest.cs
index 6ec0cf1..29423ff 100644
--- a/src/ProtocolBuffers.Test/ExtendableMessageTest.cs
+++ b/src/ProtocolBuffers.Test/ExtendableMessageTest.cs
@@ -1,192 +1,202 @@
-﻿#region Copyright notice and license
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// http://github.com/jskeet/dotnet-protobufs/
-// Original C++/Java/Python code:
-// http://code.google.com/p/protobuf/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-#endregion
-
-using System;
-using System.Collections.Generic;
-using Google.ProtocolBuffers;
-using Google.ProtocolBuffers.TestProtos;
-using NUnit.Framework;
-
-namespace Google.ProtocolBuffers {
-  [TestFixture]
-  public class ExtendableMessageTest {
-
-    [Test, ExpectedException(typeof(ArgumentException))]
-    public void ExtensionWriterInvalidExtension() {
-      TestPackedExtensions.CreateBuilder()[UnitTestProtoFile.OptionalForeignMessageExtension.Descriptor] =
-        ForeignMessage.DefaultInstance;
-    }
-
-    [Test]
-    public void ExtensionWriterTest() {
-      TestAllExtensions.Builder builder = TestAllExtensions.CreateBuilder()
-        .SetExtension(UnitTestProtoFile.DefaultBoolExtension, true)
-        .SetExtension(UnitTestProtoFile.DefaultBytesExtension, ByteString.CopyFromUtf8("123"))
-        .SetExtension(UnitTestProtoFile.DefaultCordExtension, "123")
-        .SetExtension(UnitTestProtoFile.DefaultDoubleExtension, 123)
-        .SetExtension(UnitTestProtoFile.DefaultFixed32Extension, 123u)
-        .SetExtension(UnitTestProtoFile.DefaultFixed64Extension, 123u)
-        .SetExtension(UnitTestProtoFile.DefaultFloatExtension, 123)
-        .SetExtension(UnitTestProtoFile.DefaultForeignEnumExtension, ForeignEnum.FOREIGN_BAZ)
-        .SetExtension(UnitTestProtoFile.DefaultImportEnumExtension, ImportEnum.IMPORT_BAZ)
-        .SetExtension(UnitTestProtoFile.DefaultInt32Extension, 123)
-        .SetExtension(UnitTestProtoFile.DefaultInt64Extension, 123)
-        .SetExtension(UnitTestProtoFile.DefaultNestedEnumExtension, TestAllTypes.Types.NestedEnum.FOO)
-        .SetExtension(UnitTestProtoFile.DefaultSfixed32Extension, 123)
-        .SetExtension(UnitTestProtoFile.DefaultSfixed64Extension, 123)
-        .SetExtension(UnitTestProtoFile.DefaultSint32Extension, 123)
-        .SetExtension(UnitTestProtoFile.DefaultSint64Extension, 123)
-        .SetExtension(UnitTestProtoFile.DefaultStringExtension, "123")
-        .SetExtension(UnitTestProtoFile.DefaultStringPieceExtension, "123")
-        .SetExtension(UnitTestProtoFile.DefaultUint32Extension, 123u)
-        .SetExtension(UnitTestProtoFile.DefaultUint64Extension, 123u)
-        //Optional
-        .SetExtension(UnitTestProtoFile.OptionalBoolExtension, true)
-        .SetExtension(UnitTestProtoFile.OptionalBytesExtension, ByteString.CopyFromUtf8("123"))
-        .SetExtension(UnitTestProtoFile.OptionalCordExtension, "123")
-        .SetExtension(UnitTestProtoFile.OptionalDoubleExtension, 123)
-        .SetExtension(UnitTestProtoFile.OptionalFixed32Extension, 123u)
-        .SetExtension(UnitTestProtoFile.OptionalFixed64Extension, 123u)
-        .SetExtension(UnitTestProtoFile.OptionalFloatExtension, 123)
-        .SetExtension(UnitTestProtoFile.OptionalForeignEnumExtension, ForeignEnum.FOREIGN_BAZ)
-        .SetExtension(UnitTestProtoFile.OptionalImportEnumExtension, ImportEnum.IMPORT_BAZ)
-        .SetExtension(UnitTestProtoFile.OptionalInt32Extension, 123)
-        .SetExtension(UnitTestProtoFile.OptionalInt64Extension, 123)
-        .SetExtension(UnitTestProtoFile.OptionalNestedEnumExtension, TestAllTypes.Types.NestedEnum.FOO)
-        .SetExtension(UnitTestProtoFile.OptionalSfixed32Extension, 123)
-        .SetExtension(UnitTestProtoFile.OptionalSfixed64Extension, 123)
-        .SetExtension(UnitTestProtoFile.OptionalSint32Extension, 123)
-        .SetExtension(UnitTestProtoFile.OptionalSint64Extension, 123)
-        .SetExtension(UnitTestProtoFile.OptionalStringExtension, "123")
-        .SetExtension(UnitTestProtoFile.OptionalStringPieceExtension, "123")
-        .SetExtension(UnitTestProtoFile.OptionalUint32Extension, 123u)
-        .SetExtension(UnitTestProtoFile.OptionalUint64Extension, 123u)
-        //Repeated
-        .AddExtension(UnitTestProtoFile.RepeatedBoolExtension, true)
-        .AddExtension(UnitTestProtoFile.RepeatedBytesExtension, ByteString.CopyFromUtf8("123"))
-        .AddExtension(UnitTestProtoFile.RepeatedCordExtension, "123")
-        .AddExtension(UnitTestProtoFile.RepeatedDoubleExtension, 123)
-        .AddExtension(UnitTestProtoFile.RepeatedFixed32Extension, 123u)
-        .AddExtension(UnitTestProtoFile.RepeatedFixed64Extension, 123u)
-        .AddExtension(UnitTestProtoFile.RepeatedFloatExtension, 123)
-        .AddExtension(UnitTestProtoFile.RepeatedForeignEnumExtension, ForeignEnum.FOREIGN_BAZ)
-        .AddExtension(UnitTestProtoFile.RepeatedImportEnumExtension, ImportEnum.IMPORT_BAZ)
-        .AddExtension(UnitTestProtoFile.RepeatedInt32Extension, 123)
-        .AddExtension(UnitTestProtoFile.RepeatedInt64Extension, 123)
-        .AddExtension(UnitTestProtoFile.RepeatedNestedEnumExtension, TestAllTypes.Types.NestedEnum.FOO)
-        .AddExtension(UnitTestProtoFile.RepeatedSfixed32Extension, 123)
-        .AddExtension(UnitTestProtoFile.RepeatedSfixed64Extension, 123)
-        .AddExtension(UnitTestProtoFile.RepeatedSint32Extension, 123)
-        .AddExtension(UnitTestProtoFile.RepeatedSint64Extension, 123)
-        .AddExtension(UnitTestProtoFile.RepeatedStringExtension, "123")
-        .AddExtension(UnitTestProtoFile.RepeatedStringPieceExtension, "123")
-        .AddExtension(UnitTestProtoFile.RepeatedUint32Extension, 123u)
-        .AddExtension(UnitTestProtoFile.RepeatedUint64Extension, 123u)
-        ;
-      TestAllExtensions msg = builder.Build();
-
-      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
-      UnitTestProtoFile.RegisterAllExtensions(registry);
-
-      TestAllExtensions.Builder copyBuilder = TestAllExtensions.CreateBuilder().MergeFrom(msg.ToByteArray(), registry);
-      TestAllExtensions copy = copyBuilder.Build();
-
-      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
-
-      Assert.AreEqual(true, copy.GetExtension(UnitTestProtoFile.DefaultBoolExtension));
-      Assert.AreEqual(ByteString.CopyFromUtf8("123"), copy.GetExtension(UnitTestProtoFile.DefaultBytesExtension));
-      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.DefaultCordExtension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultDoubleExtension));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultFixed32Extension));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultFixed64Extension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultFloatExtension));
-      Assert.AreEqual(ForeignEnum.FOREIGN_BAZ, copy.GetExtension(UnitTestProtoFile.DefaultForeignEnumExtension));
-      Assert.AreEqual(ImportEnum.IMPORT_BAZ, copy.GetExtension(UnitTestProtoFile.DefaultImportEnumExtension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultInt32Extension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultInt64Extension));
-      Assert.AreEqual(TestAllTypes.Types.NestedEnum.FOO, copy.GetExtension(UnitTestProtoFile.DefaultNestedEnumExtension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSfixed32Extension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSfixed64Extension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSint32Extension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSint64Extension));
-      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.DefaultStringExtension));
-      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.DefaultStringPieceExtension));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultUint32Extension));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultUint64Extension));
-
-      Assert.AreEqual(true, copy.GetExtension(UnitTestProtoFile.OptionalBoolExtension));
-      Assert.AreEqual(ByteString.CopyFromUtf8("123"), copy.GetExtension(UnitTestProtoFile.OptionalBytesExtension));
-      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.OptionalCordExtension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalDoubleExtension));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalFixed32Extension));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalFixed64Extension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalFloatExtension));
-      Assert.AreEqual(ForeignEnum.FOREIGN_BAZ, copy.GetExtension(UnitTestProtoFile.OptionalForeignEnumExtension));
-      Assert.AreEqual(ImportEnum.IMPORT_BAZ, copy.GetExtension(UnitTestProtoFile.OptionalImportEnumExtension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalInt32Extension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalInt64Extension));
-      Assert.AreEqual(TestAllTypes.Types.NestedEnum.FOO, copy.GetExtension(UnitTestProtoFile.OptionalNestedEnumExtension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSfixed32Extension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSfixed64Extension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSint32Extension));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSint64Extension));
-      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.OptionalStringExtension));
-      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.OptionalStringPieceExtension));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalUint32Extension));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalUint64Extension));
-
-      Assert.AreEqual(true, copy.GetExtension(UnitTestProtoFile.RepeatedBoolExtension, 0));
-      Assert.AreEqual(ByteString.CopyFromUtf8("123"), copy.GetExtension(UnitTestProtoFile.RepeatedBytesExtension, 0));
-      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.RepeatedCordExtension, 0));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedDoubleExtension, 0));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedFixed32Extension, 0));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedFixed64Extension, 0));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedFloatExtension, 0));
-      Assert.AreEqual(ForeignEnum.FOREIGN_BAZ, copy.GetExtension(UnitTestProtoFile.RepeatedForeignEnumExtension, 0));
-      Assert.AreEqual(ImportEnum.IMPORT_BAZ, copy.GetExtension(UnitTestProtoFile.RepeatedImportEnumExtension, 0));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedInt32Extension, 0));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedInt64Extension, 0));
-      Assert.AreEqual(TestAllTypes.Types.NestedEnum.FOO, copy.GetExtension(UnitTestProtoFile.RepeatedNestedEnumExtension, 0));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSfixed32Extension, 0));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSfixed64Extension, 0));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSint32Extension, 0));
-      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSint64Extension, 0));
-      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.RepeatedStringExtension, 0));
-      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.RepeatedStringPieceExtension, 0));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedUint32Extension, 0));
-      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedUint64Extension, 0));
-    }
-
-  }
-}
+#region Copyright notice and license
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://github.com/jskeet/dotnet-protobufs/
+// Original C++/Java/Python code:
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#endregion
+
+using System;
+using System.Collections.Generic;
+using Google.ProtocolBuffers;
+using Google.ProtocolBuffers.TestProtos;
+using NUnit.Framework;
+
+namespace Google.ProtocolBuffers
+{
+    [TestFixture]
+    public class ExtendableMessageTest
+    {
+        [Test, ExpectedException(typeof (ArgumentException))]
+        public void ExtensionWriterInvalidExtension()
+        {
+            TestPackedExtensions.CreateBuilder()[UnitTestProtoFile.OptionalForeignMessageExtension.Descriptor] =
+                ForeignMessage.DefaultInstance;
+        }
+
+        [Test]
+        public void ExtensionWriterTest()
+        {
+            TestAllExtensions.Builder builder = TestAllExtensions.CreateBuilder()
+                .SetExtension(UnitTestProtoFile.DefaultBoolExtension, true)
+                .SetExtension(UnitTestProtoFile.DefaultBytesExtension, ByteString.CopyFromUtf8("123"))
+                .SetExtension(UnitTestProtoFile.DefaultCordExtension, "123")
+                .SetExtension(UnitTestProtoFile.DefaultDoubleExtension, 123)
+                .SetExtension(UnitTestProtoFile.DefaultFixed32Extension, 123u)
+                .SetExtension(UnitTestProtoFile.DefaultFixed64Extension, 123u)
+                .SetExtension(UnitTestProtoFile.DefaultFloatExtension, 123)
+                .SetExtension(UnitTestProtoFile.DefaultForeignEnumExtension, ForeignEnum.FOREIGN_BAZ)
+                .SetExtension(UnitTestProtoFile.DefaultImportEnumExtension, ImportEnum.IMPORT_BAZ)
+                .SetExtension(UnitTestProtoFile.DefaultInt32Extension, 123)
+                .SetExtension(UnitTestProtoFile.DefaultInt64Extension, 123)
+                .SetExtension(UnitTestProtoFile.DefaultNestedEnumExtension, TestAllTypes.Types.NestedEnum.FOO)
+                .SetExtension(UnitTestProtoFile.DefaultSfixed32Extension, 123)
+                .SetExtension(UnitTestProtoFile.DefaultSfixed64Extension, 123)
+                .SetExtension(UnitTestProtoFile.DefaultSint32Extension, 123)
+                .SetExtension(UnitTestProtoFile.DefaultSint64Extension, 123)
+                .SetExtension(UnitTestProtoFile.DefaultStringExtension, "123")
+                .SetExtension(UnitTestProtoFile.DefaultStringPieceExtension, "123")
+                .SetExtension(UnitTestProtoFile.DefaultUint32Extension, 123u)
+                .SetExtension(UnitTestProtoFile.DefaultUint64Extension, 123u)
+                //Optional
+                .SetExtension(UnitTestProtoFile.OptionalBoolExtension, true)
+                .SetExtension(UnitTestProtoFile.OptionalBytesExtension, ByteString.CopyFromUtf8("123"))
+                .SetExtension(UnitTestProtoFile.OptionalCordExtension, "123")
+                .SetExtension(UnitTestProtoFile.OptionalDoubleExtension, 123)
+                .SetExtension(UnitTestProtoFile.OptionalFixed32Extension, 123u)
+                .SetExtension(UnitTestProtoFile.OptionalFixed64Extension, 123u)
+                .SetExtension(UnitTestProtoFile.OptionalFloatExtension, 123)
+                .SetExtension(UnitTestProtoFile.OptionalForeignEnumExtension, ForeignEnum.FOREIGN_BAZ)
+                .SetExtension(UnitTestProtoFile.OptionalImportEnumExtension, ImportEnum.IMPORT_BAZ)
+                .SetExtension(UnitTestProtoFile.OptionalInt32Extension, 123)
+                .SetExtension(UnitTestProtoFile.OptionalInt64Extension, 123)
+                .SetExtension(UnitTestProtoFile.OptionalNestedEnumExtension, TestAllTypes.Types.NestedEnum.FOO)
+                .SetExtension(UnitTestProtoFile.OptionalSfixed32Extension, 123)
+                .SetExtension(UnitTestProtoFile.OptionalSfixed64Extension, 123)
+                .SetExtension(UnitTestProtoFile.OptionalSint32Extension, 123)
+                .SetExtension(UnitTestProtoFile.OptionalSint64Extension, 123)
+                .SetExtension(UnitTestProtoFile.OptionalStringExtension, "123")
+                .SetExtension(UnitTestProtoFile.OptionalStringPieceExtension, "123")
+                .SetExtension(UnitTestProtoFile.OptionalUint32Extension, 123u)
+                .SetExtension(UnitTestProtoFile.OptionalUint64Extension, 123u)
+                //Repeated
+                .AddExtension(UnitTestProtoFile.RepeatedBoolExtension, true)
+                .AddExtension(UnitTestProtoFile.RepeatedBytesExtension, ByteString.CopyFromUtf8("123"))
+                .AddExtension(UnitTestProtoFile.RepeatedCordExtension, "123")
+                .AddExtension(UnitTestProtoFile.RepeatedDoubleExtension, 123)
+                .AddExtension(UnitTestProtoFile.RepeatedFixed32Extension, 123u)
+                .AddExtension(UnitTestProtoFile.RepeatedFixed64Extension, 123u)
+                .AddExtension(UnitTestProtoFile.RepeatedFloatExtension, 123)
+                .AddExtension(UnitTestProtoFile.RepeatedForeignEnumExtension, ForeignEnum.FOREIGN_BAZ)
+                .AddExtension(UnitTestProtoFile.RepeatedImportEnumExtension, ImportEnum.IMPORT_BAZ)
+                .AddExtension(UnitTestProtoFile.RepeatedInt32Extension, 123)
+                .AddExtension(UnitTestProtoFile.RepeatedInt64Extension, 123)
+                .AddExtension(UnitTestProtoFile.RepeatedNestedEnumExtension, TestAllTypes.Types.NestedEnum.FOO)
+                .AddExtension(UnitTestProtoFile.RepeatedSfixed32Extension, 123)
+                .AddExtension(UnitTestProtoFile.RepeatedSfixed64Extension, 123)
+                .AddExtension(UnitTestProtoFile.RepeatedSint32Extension, 123)
+                .AddExtension(UnitTestProtoFile.RepeatedSint64Extension, 123)
+                .AddExtension(UnitTestProtoFile.RepeatedStringExtension, "123")
+                .AddExtension(UnitTestProtoFile.RepeatedStringPieceExtension, "123")
+                .AddExtension(UnitTestProtoFile.RepeatedUint32Extension, 123u)
+                .AddExtension(UnitTestProtoFile.RepeatedUint64Extension, 123u)
+                ;
+            TestAllExtensions msg = builder.Build();
+
+            ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+            UnitTestProtoFile.RegisterAllExtensions(registry);
+
+            TestAllExtensions.Builder copyBuilder = TestAllExtensions.CreateBuilder().MergeFrom(msg.ToByteArray(),
+                                                                                                registry);
+            TestAllExtensions copy = copyBuilder.Build();
+
+            Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+
+            Assert.AreEqual(true, copy.GetExtension(UnitTestProtoFile.DefaultBoolExtension));
+            Assert.AreEqual(ByteString.CopyFromUtf8("123"), copy.GetExtension(UnitTestProtoFile.DefaultBytesExtension));
+            Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.DefaultCordExtension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultDoubleExtension));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultFixed32Extension));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultFixed64Extension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultFloatExtension));
+            Assert.AreEqual(ForeignEnum.FOREIGN_BAZ, copy.GetExtension(UnitTestProtoFile.DefaultForeignEnumExtension));
+            Assert.AreEqual(ImportEnum.IMPORT_BAZ, copy.GetExtension(UnitTestProtoFile.DefaultImportEnumExtension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultInt32Extension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultInt64Extension));
+            Assert.AreEqual(TestAllTypes.Types.NestedEnum.FOO,
+                            copy.GetExtension(UnitTestProtoFile.DefaultNestedEnumExtension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSfixed32Extension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSfixed64Extension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSint32Extension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSint64Extension));
+            Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.DefaultStringExtension));
+            Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.DefaultStringPieceExtension));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultUint32Extension));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultUint64Extension));
+
+            Assert.AreEqual(true, copy.GetExtension(UnitTestProtoFile.OptionalBoolExtension));
+            Assert.AreEqual(ByteString.CopyFromUtf8("123"), copy.GetExtension(UnitTestProtoFile.OptionalBytesExtension));
+            Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.OptionalCordExtension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalDoubleExtension));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalFixed32Extension));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalFixed64Extension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalFloatExtension));
+            Assert.AreEqual(ForeignEnum.FOREIGN_BAZ, copy.GetExtension(UnitTestProtoFile.OptionalForeignEnumExtension));
+            Assert.AreEqual(ImportEnum.IMPORT_BAZ, copy.GetExtension(UnitTestProtoFile.OptionalImportEnumExtension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalInt32Extension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalInt64Extension));
+            Assert.AreEqual(TestAllTypes.Types.NestedEnum.FOO,
+                            copy.GetExtension(UnitTestProtoFile.OptionalNestedEnumExtension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSfixed32Extension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSfixed64Extension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSint32Extension));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSint64Extension));
+            Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.OptionalStringExtension));
+            Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.OptionalStringPieceExtension));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalUint32Extension));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalUint64Extension));
+
+            Assert.AreEqual(true, copy.GetExtension(UnitTestProtoFile.RepeatedBoolExtension, 0));
+            Assert.AreEqual(ByteString.CopyFromUtf8("123"),
+                            copy.GetExtension(UnitTestProtoFile.RepeatedBytesExtension, 0));
+            Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.RepeatedCordExtension, 0));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedDoubleExtension, 0));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedFixed32Extension, 0));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedFixed64Extension, 0));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedFloatExtension, 0));
+            Assert.AreEqual(ForeignEnum.FOREIGN_BAZ,
+                            copy.GetExtension(UnitTestProtoFile.RepeatedForeignEnumExtension, 0));
+            Assert.AreEqual(ImportEnum.IMPORT_BAZ, copy.GetExtension(UnitTestProtoFile.RepeatedImportEnumExtension, 0));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedInt32Extension, 0));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedInt64Extension, 0));
+            Assert.AreEqual(TestAllTypes.Types.NestedEnum.FOO,
+                            copy.GetExtension(UnitTestProtoFile.RepeatedNestedEnumExtension, 0));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSfixed32Extension, 0));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSfixed64Extension, 0));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSint32Extension, 0));
+            Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSint64Extension, 0));
+            Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.RepeatedStringExtension, 0));
+            Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.RepeatedStringPieceExtension, 0));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedUint32Extension, 0));
+            Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedUint64Extension, 0));
+        }
+    }
+}
\ No newline at end of file