diff --git a/examples/csharp/Helloworld/Greeter/Helloworld.cs b/examples/csharp/Helloworld/Greeter/Helloworld.cs
index ecfc8e131cb..e008ec27e54 100644
--- a/examples/csharp/Helloworld/Greeter/Helloworld.cs
+++ b/examples/csharp/Helloworld/Greeter/Helloworld.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: helloworld.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: helloworld.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -44,6 +46,7 @@ namespace Helloworld {
   /// </summary>
   public sealed partial class HelloRequest : pb::IMessage<HelloRequest> {
     private static readonly pb::MessageParser<HelloRequest> _parser = new pb::MessageParser<HelloRequest>(() => new HelloRequest());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HelloRequest> Parser { get { return _parser; } }
 
@@ -67,6 +70,7 @@ namespace Helloworld {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HelloRequest(HelloRequest other) : this() {
       name_ = other.name_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -99,13 +103,16 @@ namespace Helloworld {
         return true;
       }
       if (Name != other.Name) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -120,6 +127,9 @@ namespace Helloworld {
         output.WriteRawTag(10);
         output.WriteString(Name);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -128,6 +138,9 @@ namespace Helloworld {
       if (Name.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(Name);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -139,6 +152,7 @@ namespace Helloworld {
       if (other.Name.Length != 0) {
         Name = other.Name;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -147,7 +161,7 @@ namespace Helloworld {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Name = input.ReadString();
@@ -164,6 +178,7 @@ namespace Helloworld {
   /// </summary>
   public sealed partial class HelloReply : pb::IMessage<HelloReply> {
     private static readonly pb::MessageParser<HelloReply> _parser = new pb::MessageParser<HelloReply>(() => new HelloReply());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HelloReply> Parser { get { return _parser; } }
 
@@ -187,6 +202,7 @@ namespace Helloworld {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HelloReply(HelloReply other) : this() {
       message_ = other.message_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -219,13 +235,16 @@ namespace Helloworld {
         return true;
       }
       if (Message != other.Message) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Message.Length != 0) hash ^= Message.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -240,6 +259,9 @@ namespace Helloworld {
         output.WriteRawTag(10);
         output.WriteString(Message);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -248,6 +270,9 @@ namespace Helloworld {
       if (Message.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(Message);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -259,6 +284,7 @@ namespace Helloworld {
       if (other.Message.Length != 0) {
         Message = other.Message;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -267,7 +293,7 @@ namespace Helloworld {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Message = input.ReadString();
diff --git a/examples/csharp/Helloworld/Greeter/HelloworldGrpc.cs b/examples/csharp/Helloworld/Greeter/HelloworldGrpc.cs
index c808884e579..d6b959adc64 100644
--- a/examples/csharp/Helloworld/Greeter/HelloworldGrpc.cs
+++ b/examples/csharp/Helloworld/Greeter/HelloworldGrpc.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: helloworld.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: helloworld.proto
+// </auto-generated>
 // Original file comments:
 // Copyright 2015 gRPC authors.
 //
@@ -15,12 +17,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 //
-#pragma warning disable 1591
+#pragma warning disable 0414, 1591
 #region Designer generated code
 
-using System;
-using System.Threading;
-using System.Threading.Tasks;
 using grpc = global::Grpc.Core;
 
 namespace Helloworld {
@@ -31,15 +30,15 @@ namespace Helloworld {
   {
     static readonly string __ServiceName = "helloworld.Greeter";
 
-    static readonly grpc::Marshaller<global::Helloworld.HelloRequest> __Marshaller_HelloRequest = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Helloworld.HelloRequest.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Helloworld.HelloReply> __Marshaller_HelloReply = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Helloworld.HelloReply.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Helloworld.HelloRequest> __Marshaller_helloworld_HelloRequest = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Helloworld.HelloRequest.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Helloworld.HelloReply> __Marshaller_helloworld_HelloReply = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Helloworld.HelloReply.Parser.ParseFrom);
 
     static readonly grpc::Method<global::Helloworld.HelloRequest, global::Helloworld.HelloReply> __Method_SayHello = new grpc::Method<global::Helloworld.HelloRequest, global::Helloworld.HelloReply>(
         grpc::MethodType.Unary,
         __ServiceName,
         "SayHello",
-        __Marshaller_HelloRequest,
-        __Marshaller_HelloReply);
+        __Marshaller_helloworld_HelloRequest,
+        __Marshaller_helloworld_HelloReply);
 
     /// <summary>Service descriptor</summary>
     public static global::Google.Protobuf.Reflection.ServiceDescriptor Descriptor
@@ -94,7 +93,7 @@ namespace Helloworld {
       /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
       /// <param name="cancellationToken">An optional token for canceling the call.</param>
       /// <returns>The response received from the server.</returns>
-      public virtual global::Helloworld.HelloReply SayHello(global::Helloworld.HelloRequest request, grpc::Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken))
+      public virtual global::Helloworld.HelloReply SayHello(global::Helloworld.HelloRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
       {
         return SayHello(request, new grpc::CallOptions(headers, deadline, cancellationToken));
       }
@@ -116,7 +115,7 @@ namespace Helloworld {
       /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
       /// <param name="cancellationToken">An optional token for canceling the call.</param>
       /// <returns>The call object.</returns>
-      public virtual grpc::AsyncUnaryCall<global::Helloworld.HelloReply> SayHelloAsync(global::Helloworld.HelloRequest request, grpc::Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken))
+      public virtual grpc::AsyncUnaryCall<global::Helloworld.HelloReply> SayHelloAsync(global::Helloworld.HelloRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
       {
         return SayHelloAsync(request, new grpc::CallOptions(headers, deadline, cancellationToken));
       }
diff --git a/examples/csharp/HelloworldLegacyCsproj/Greeter/Helloworld.cs b/examples/csharp/HelloworldLegacyCsproj/Greeter/Helloworld.cs
index ecfc8e131cb..e008ec27e54 100644
--- a/examples/csharp/HelloworldLegacyCsproj/Greeter/Helloworld.cs
+++ b/examples/csharp/HelloworldLegacyCsproj/Greeter/Helloworld.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: helloworld.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: helloworld.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -44,6 +46,7 @@ namespace Helloworld {
   /// </summary>
   public sealed partial class HelloRequest : pb::IMessage<HelloRequest> {
     private static readonly pb::MessageParser<HelloRequest> _parser = new pb::MessageParser<HelloRequest>(() => new HelloRequest());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HelloRequest> Parser { get { return _parser; } }
 
@@ -67,6 +70,7 @@ namespace Helloworld {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HelloRequest(HelloRequest other) : this() {
       name_ = other.name_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -99,13 +103,16 @@ namespace Helloworld {
         return true;
       }
       if (Name != other.Name) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -120,6 +127,9 @@ namespace Helloworld {
         output.WriteRawTag(10);
         output.WriteString(Name);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -128,6 +138,9 @@ namespace Helloworld {
       if (Name.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(Name);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -139,6 +152,7 @@ namespace Helloworld {
       if (other.Name.Length != 0) {
         Name = other.Name;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -147,7 +161,7 @@ namespace Helloworld {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Name = input.ReadString();
@@ -164,6 +178,7 @@ namespace Helloworld {
   /// </summary>
   public sealed partial class HelloReply : pb::IMessage<HelloReply> {
     private static readonly pb::MessageParser<HelloReply> _parser = new pb::MessageParser<HelloReply>(() => new HelloReply());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HelloReply> Parser { get { return _parser; } }
 
@@ -187,6 +202,7 @@ namespace Helloworld {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HelloReply(HelloReply other) : this() {
       message_ = other.message_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -219,13 +235,16 @@ namespace Helloworld {
         return true;
       }
       if (Message != other.Message) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Message.Length != 0) hash ^= Message.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -240,6 +259,9 @@ namespace Helloworld {
         output.WriteRawTag(10);
         output.WriteString(Message);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -248,6 +270,9 @@ namespace Helloworld {
       if (Message.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(Message);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -259,6 +284,7 @@ namespace Helloworld {
       if (other.Message.Length != 0) {
         Message = other.Message;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -267,7 +293,7 @@ namespace Helloworld {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Message = input.ReadString();
diff --git a/examples/csharp/HelloworldLegacyCsproj/Greeter/HelloworldGrpc.cs b/examples/csharp/HelloworldLegacyCsproj/Greeter/HelloworldGrpc.cs
index c808884e579..d6b959adc64 100644
--- a/examples/csharp/HelloworldLegacyCsproj/Greeter/HelloworldGrpc.cs
+++ b/examples/csharp/HelloworldLegacyCsproj/Greeter/HelloworldGrpc.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: helloworld.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: helloworld.proto
+// </auto-generated>
 // Original file comments:
 // Copyright 2015 gRPC authors.
 //
@@ -15,12 +17,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 //
-#pragma warning disable 1591
+#pragma warning disable 0414, 1591
 #region Designer generated code
 
-using System;
-using System.Threading;
-using System.Threading.Tasks;
 using grpc = global::Grpc.Core;
 
 namespace Helloworld {
@@ -31,15 +30,15 @@ namespace Helloworld {
   {
     static readonly string __ServiceName = "helloworld.Greeter";
 
-    static readonly grpc::Marshaller<global::Helloworld.HelloRequest> __Marshaller_HelloRequest = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Helloworld.HelloRequest.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Helloworld.HelloReply> __Marshaller_HelloReply = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Helloworld.HelloReply.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Helloworld.HelloRequest> __Marshaller_helloworld_HelloRequest = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Helloworld.HelloRequest.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Helloworld.HelloReply> __Marshaller_helloworld_HelloReply = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Helloworld.HelloReply.Parser.ParseFrom);
 
     static readonly grpc::Method<global::Helloworld.HelloRequest, global::Helloworld.HelloReply> __Method_SayHello = new grpc::Method<global::Helloworld.HelloRequest, global::Helloworld.HelloReply>(
         grpc::MethodType.Unary,
         __ServiceName,
         "SayHello",
-        __Marshaller_HelloRequest,
-        __Marshaller_HelloReply);
+        __Marshaller_helloworld_HelloRequest,
+        __Marshaller_helloworld_HelloReply);
 
     /// <summary>Service descriptor</summary>
     public static global::Google.Protobuf.Reflection.ServiceDescriptor Descriptor
@@ -94,7 +93,7 @@ namespace Helloworld {
       /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
       /// <param name="cancellationToken">An optional token for canceling the call.</param>
       /// <returns>The response received from the server.</returns>
-      public virtual global::Helloworld.HelloReply SayHello(global::Helloworld.HelloRequest request, grpc::Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken))
+      public virtual global::Helloworld.HelloReply SayHello(global::Helloworld.HelloRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
       {
         return SayHello(request, new grpc::CallOptions(headers, deadline, cancellationToken));
       }
@@ -116,7 +115,7 @@ namespace Helloworld {
       /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
       /// <param name="cancellationToken">An optional token for canceling the call.</param>
       /// <returns>The call object.</returns>
-      public virtual grpc::AsyncUnaryCall<global::Helloworld.HelloReply> SayHelloAsync(global::Helloworld.HelloRequest request, grpc::Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken))
+      public virtual grpc::AsyncUnaryCall<global::Helloworld.HelloReply> SayHelloAsync(global::Helloworld.HelloRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
       {
         return SayHelloAsync(request, new grpc::CallOptions(headers, deadline, cancellationToken));
       }
diff --git a/examples/csharp/RouteGuide/RouteGuide/RouteGuide.cs b/examples/csharp/RouteGuide/RouteGuide/RouteGuide.cs
index 603809ee76f..10c9aec5f80 100644
--- a/examples/csharp/RouteGuide/RouteGuide/RouteGuide.cs
+++ b/examples/csharp/RouteGuide/RouteGuide/RouteGuide.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: route_guide.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: route_guide.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -60,6 +62,7 @@ namespace Routeguide {
   /// </summary>
   public sealed partial class Point : pb::IMessage<Point> {
     private static readonly pb::MessageParser<Point> _parser = new pb::MessageParser<Point>(() => new Point());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Point> Parser { get { return _parser; } }
 
@@ -84,6 +87,7 @@ namespace Routeguide {
     public Point(Point other) : this() {
       latitude_ = other.latitude_;
       longitude_ = other.longitude_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -128,7 +132,7 @@ namespace Routeguide {
       }
       if (Latitude != other.Latitude) return false;
       if (Longitude != other.Longitude) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -136,6 +140,9 @@ namespace Routeguide {
       int hash = 1;
       if (Latitude != 0) hash ^= Latitude.GetHashCode();
       if (Longitude != 0) hash ^= Longitude.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -154,6 +161,9 @@ namespace Routeguide {
         output.WriteRawTag(16);
         output.WriteInt32(Longitude);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -165,6 +175,9 @@ namespace Routeguide {
       if (Longitude != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(Longitude);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -179,6 +192,7 @@ namespace Routeguide {
       if (other.Longitude != 0) {
         Longitude = other.Longitude;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -187,7 +201,7 @@ namespace Routeguide {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Latitude = input.ReadInt32();
@@ -209,6 +223,7 @@ namespace Routeguide {
   /// </summary>
   public sealed partial class Rectangle : pb::IMessage<Rectangle> {
     private static readonly pb::MessageParser<Rectangle> _parser = new pb::MessageParser<Rectangle>(() => new Rectangle());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Rectangle> Parser { get { return _parser; } }
 
@@ -231,8 +246,9 @@ namespace Routeguide {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Rectangle(Rectangle other) : this() {
-      Lo = other.lo_ != null ? other.Lo.Clone() : null;
-      Hi = other.hi_ != null ? other.Hi.Clone() : null;
+      lo_ = other.lo_ != null ? other.lo_.Clone() : null;
+      hi_ = other.hi_ != null ? other.hi_.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -283,7 +299,7 @@ namespace Routeguide {
       }
       if (!object.Equals(Lo, other.Lo)) return false;
       if (!object.Equals(Hi, other.Hi)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -291,6 +307,9 @@ namespace Routeguide {
       int hash = 1;
       if (lo_ != null) hash ^= Lo.GetHashCode();
       if (hi_ != null) hash ^= Hi.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -309,6 +328,9 @@ namespace Routeguide {
         output.WriteRawTag(18);
         output.WriteMessage(Hi);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -320,6 +342,9 @@ namespace Routeguide {
       if (hi_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Hi);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -340,6 +365,7 @@ namespace Routeguide {
         }
         Hi.MergeFrom(other.Hi);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -348,7 +374,7 @@ namespace Routeguide {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             if (lo_ == null) {
@@ -377,6 +403,7 @@ namespace Routeguide {
   /// </summary>
   public sealed partial class Feature : pb::IMessage<Feature> {
     private static readonly pb::MessageParser<Feature> _parser = new pb::MessageParser<Feature>(() => new Feature());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Feature> Parser { get { return _parser; } }
 
@@ -400,7 +427,8 @@ namespace Routeguide {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Feature(Feature other) : this() {
       name_ = other.name_;
-      Location = other.location_ != null ? other.Location.Clone() : null;
+      location_ = other.location_ != null ? other.location_.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -451,7 +479,7 @@ namespace Routeguide {
       }
       if (Name != other.Name) return false;
       if (!object.Equals(Location, other.Location)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -459,6 +487,9 @@ namespace Routeguide {
       int hash = 1;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       if (location_ != null) hash ^= Location.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -477,6 +508,9 @@ namespace Routeguide {
         output.WriteRawTag(18);
         output.WriteMessage(Location);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -488,6 +522,9 @@ namespace Routeguide {
       if (location_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Location);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -505,6 +542,7 @@ namespace Routeguide {
         }
         Location.MergeFrom(other.Location);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -513,7 +551,7 @@ namespace Routeguide {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Name = input.ReadString();
@@ -537,6 +575,7 @@ namespace Routeguide {
   /// </summary>
   public sealed partial class RouteNote : pb::IMessage<RouteNote> {
     private static readonly pb::MessageParser<RouteNote> _parser = new pb::MessageParser<RouteNote>(() => new RouteNote());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<RouteNote> Parser { get { return _parser; } }
 
@@ -559,8 +598,9 @@ namespace Routeguide {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public RouteNote(RouteNote other) : this() {
-      Location = other.location_ != null ? other.Location.Clone() : null;
+      location_ = other.location_ != null ? other.location_.Clone() : null;
       message_ = other.message_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -611,7 +651,7 @@ namespace Routeguide {
       }
       if (!object.Equals(Location, other.Location)) return false;
       if (Message != other.Message) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -619,6 +659,9 @@ namespace Routeguide {
       int hash = 1;
       if (location_ != null) hash ^= Location.GetHashCode();
       if (Message.Length != 0) hash ^= Message.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -637,6 +680,9 @@ namespace Routeguide {
         output.WriteRawTag(18);
         output.WriteString(Message);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -648,6 +694,9 @@ namespace Routeguide {
       if (Message.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(Message);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -665,6 +714,7 @@ namespace Routeguide {
       if (other.Message.Length != 0) {
         Message = other.Message;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -673,7 +723,7 @@ namespace Routeguide {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             if (location_ == null) {
@@ -701,6 +751,7 @@ namespace Routeguide {
   /// </summary>
   public sealed partial class RouteSummary : pb::IMessage<RouteSummary> {
     private static readonly pb::MessageParser<RouteSummary> _parser = new pb::MessageParser<RouteSummary>(() => new RouteSummary());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<RouteSummary> Parser { get { return _parser; } }
 
@@ -727,6 +778,7 @@ namespace Routeguide {
       featureCount_ = other.featureCount_;
       distance_ = other.distance_;
       elapsedTime_ = other.elapsedTime_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -807,7 +859,7 @@ namespace Routeguide {
       if (FeatureCount != other.FeatureCount) return false;
       if (Distance != other.Distance) return false;
       if (ElapsedTime != other.ElapsedTime) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -817,6 +869,9 @@ namespace Routeguide {
       if (FeatureCount != 0) hash ^= FeatureCount.GetHashCode();
       if (Distance != 0) hash ^= Distance.GetHashCode();
       if (ElapsedTime != 0) hash ^= ElapsedTime.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -843,6 +898,9 @@ namespace Routeguide {
         output.WriteRawTag(32);
         output.WriteInt32(ElapsedTime);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -860,6 +918,9 @@ namespace Routeguide {
       if (ElapsedTime != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(ElapsedTime);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -880,6 +941,7 @@ namespace Routeguide {
       if (other.ElapsedTime != 0) {
         ElapsedTime = other.ElapsedTime;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -888,7 +950,7 @@ namespace Routeguide {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             PointCount = input.ReadInt32();
diff --git a/examples/csharp/RouteGuide/RouteGuide/RouteGuideGrpc.cs b/examples/csharp/RouteGuide/RouteGuide/RouteGuideGrpc.cs
index 765d5d520bc..445708e4469 100644
--- a/examples/csharp/RouteGuide/RouteGuide/RouteGuideGrpc.cs
+++ b/examples/csharp/RouteGuide/RouteGuide/RouteGuideGrpc.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: route_guide.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: route_guide.proto
+// </auto-generated>
 // Original file comments:
 // Copyright 2015 gRPC authors.
 //
@@ -15,12 +17,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 //
-#pragma warning disable 1591
+#pragma warning disable 0414, 1591
 #region Designer generated code
 
-using System;
-using System.Threading;
-using System.Threading.Tasks;
 using grpc = global::Grpc.Core;
 
 namespace Routeguide {
@@ -31,39 +30,39 @@ namespace Routeguide {
   {
     static readonly string __ServiceName = "routeguide.RouteGuide";
 
-    static readonly grpc::Marshaller<global::Routeguide.Point> __Marshaller_Point = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Routeguide.Point.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Routeguide.Feature> __Marshaller_Feature = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Routeguide.Feature.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Routeguide.Rectangle> __Marshaller_Rectangle = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Routeguide.Rectangle.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Routeguide.RouteSummary> __Marshaller_RouteSummary = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Routeguide.RouteSummary.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Routeguide.RouteNote> __Marshaller_RouteNote = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Routeguide.RouteNote.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Routeguide.Point> __Marshaller_routeguide_Point = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Routeguide.Point.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Routeguide.Feature> __Marshaller_routeguide_Feature = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Routeguide.Feature.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Routeguide.Rectangle> __Marshaller_routeguide_Rectangle = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Routeguide.Rectangle.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Routeguide.RouteSummary> __Marshaller_routeguide_RouteSummary = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Routeguide.RouteSummary.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Routeguide.RouteNote> __Marshaller_routeguide_RouteNote = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Routeguide.RouteNote.Parser.ParseFrom);
 
     static readonly grpc::Method<global::Routeguide.Point, global::Routeguide.Feature> __Method_GetFeature = new grpc::Method<global::Routeguide.Point, global::Routeguide.Feature>(
         grpc::MethodType.Unary,
         __ServiceName,
         "GetFeature",
-        __Marshaller_Point,
-        __Marshaller_Feature);
+        __Marshaller_routeguide_Point,
+        __Marshaller_routeguide_Feature);
 
     static readonly grpc::Method<global::Routeguide.Rectangle, global::Routeguide.Feature> __Method_ListFeatures = new grpc::Method<global::Routeguide.Rectangle, global::Routeguide.Feature>(
         grpc::MethodType.ServerStreaming,
         __ServiceName,
         "ListFeatures",
-        __Marshaller_Rectangle,
-        __Marshaller_Feature);
+        __Marshaller_routeguide_Rectangle,
+        __Marshaller_routeguide_Feature);
 
     static readonly grpc::Method<global::Routeguide.Point, global::Routeguide.RouteSummary> __Method_RecordRoute = new grpc::Method<global::Routeguide.Point, global::Routeguide.RouteSummary>(
         grpc::MethodType.ClientStreaming,
         __ServiceName,
         "RecordRoute",
-        __Marshaller_Point,
-        __Marshaller_RouteSummary);
+        __Marshaller_routeguide_Point,
+        __Marshaller_routeguide_RouteSummary);
 
     static readonly grpc::Method<global::Routeguide.RouteNote, global::Routeguide.RouteNote> __Method_RouteChat = new grpc::Method<global::Routeguide.RouteNote, global::Routeguide.RouteNote>(
         grpc::MethodType.DuplexStreaming,
         __ServiceName,
         "RouteChat",
-        __Marshaller_RouteNote,
-        __Marshaller_RouteNote);
+        __Marshaller_routeguide_RouteNote,
+        __Marshaller_routeguide_RouteNote);
 
     /// <summary>Service descriptor</summary>
     public static global::Google.Protobuf.Reflection.ServiceDescriptor Descriptor
@@ -174,7 +173,7 @@ namespace Routeguide {
       /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
       /// <param name="cancellationToken">An optional token for canceling the call.</param>
       /// <returns>The response received from the server.</returns>
-      public virtual global::Routeguide.Feature GetFeature(global::Routeguide.Point request, grpc::Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken))
+      public virtual global::Routeguide.Feature GetFeature(global::Routeguide.Point request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
       {
         return GetFeature(request, new grpc::CallOptions(headers, deadline, cancellationToken));
       }
@@ -206,7 +205,7 @@ namespace Routeguide {
       /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
       /// <param name="cancellationToken">An optional token for canceling the call.</param>
       /// <returns>The call object.</returns>
-      public virtual grpc::AsyncUnaryCall<global::Routeguide.Feature> GetFeatureAsync(global::Routeguide.Point request, grpc::Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken))
+      public virtual grpc::AsyncUnaryCall<global::Routeguide.Feature> GetFeatureAsync(global::Routeguide.Point request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
       {
         return GetFeatureAsync(request, new grpc::CallOptions(headers, deadline, cancellationToken));
       }
@@ -238,7 +237,7 @@ namespace Routeguide {
       /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
       /// <param name="cancellationToken">An optional token for canceling the call.</param>
       /// <returns>The call object.</returns>
-      public virtual grpc::AsyncServerStreamingCall<global::Routeguide.Feature> ListFeatures(global::Routeguide.Rectangle request, grpc::Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken))
+      public virtual grpc::AsyncServerStreamingCall<global::Routeguide.Feature> ListFeatures(global::Routeguide.Rectangle request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
       {
         return ListFeatures(request, new grpc::CallOptions(headers, deadline, cancellationToken));
       }
@@ -267,7 +266,7 @@ namespace Routeguide {
       /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
       /// <param name="cancellationToken">An optional token for canceling the call.</param>
       /// <returns>The call object.</returns>
-      public virtual grpc::AsyncClientStreamingCall<global::Routeguide.Point, global::Routeguide.RouteSummary> RecordRoute(grpc::Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken))
+      public virtual grpc::AsyncClientStreamingCall<global::Routeguide.Point, global::Routeguide.RouteSummary> RecordRoute(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
       {
         return RecordRoute(new grpc::CallOptions(headers, deadline, cancellationToken));
       }
@@ -293,7 +292,7 @@ namespace Routeguide {
       /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
       /// <param name="cancellationToken">An optional token for canceling the call.</param>
       /// <returns>The call object.</returns>
-      public virtual grpc::AsyncDuplexStreamingCall<global::Routeguide.RouteNote, global::Routeguide.RouteNote> RouteChat(grpc::Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken))
+      public virtual grpc::AsyncDuplexStreamingCall<global::Routeguide.RouteNote, global::Routeguide.RouteNote> RouteChat(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
       {
         return RouteChat(new grpc::CallOptions(headers, deadline, cancellationToken));
       }