Fix warnings in Grpc.Examples
diff --git a/src/csharp/Grpc.Examples.MathClient/Grpc.Examples.MathClient.csproj b/src/csharp/Grpc.Examples.MathClient/Grpc.Examples.MathClient.csproj
index 08df026..74deed6 100755
--- a/src/csharp/Grpc.Examples.MathClient/Grpc.Examples.MathClient.csproj
+++ b/src/csharp/Grpc.Examples.MathClient/Grpc.Examples.MathClient.csproj
@@ -9,6 +9,7 @@
     <OutputType>Exe</OutputType>
     <PackageId>Grpc.Examples.MathClient</PackageId>
     <RuntimeFrameworkVersion Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">1.0.4</RuntimeFrameworkVersion>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/csharp/Grpc.Examples.MathServer/Grpc.Examples.MathServer.csproj b/src/csharp/Grpc.Examples.MathServer/Grpc.Examples.MathServer.csproj
index a029374..1abf261 100755
--- a/src/csharp/Grpc.Examples.MathServer/Grpc.Examples.MathServer.csproj
+++ b/src/csharp/Grpc.Examples.MathServer/Grpc.Examples.MathServer.csproj
@@ -9,6 +9,7 @@
     <OutputType>Exe</OutputType>
     <PackageId>Grpc.Examples.MathServer</PackageId>
     <RuntimeFrameworkVersion Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">1.0.4</RuntimeFrameworkVersion>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/csharp/Grpc.Examples.Tests/Grpc.Examples.Tests.csproj b/src/csharp/Grpc.Examples.Tests/Grpc.Examples.Tests.csproj
index 9a8e62c..d2a13ed 100755
--- a/src/csharp/Grpc.Examples.Tests/Grpc.Examples.Tests.csproj
+++ b/src/csharp/Grpc.Examples.Tests/Grpc.Examples.Tests.csproj
@@ -10,6 +10,7 @@
     <PackageId>Grpc.Examples.Tests</PackageId>
     <PackageTargetFallback Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">$(PackageTargetFallback);portable-net45</PackageTargetFallback>
     <RuntimeFrameworkVersion Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">1.0.4</RuntimeFrameworkVersion>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/csharp/Grpc.Examples.Tests/MathClientServerTests.cs b/src/csharp/Grpc.Examples.Tests/MathClientServerTests.cs
index 8e6d685..ded80ff 100644
--- a/src/csharp/Grpc.Examples.Tests/MathClientServerTests.cs
+++ b/src/csharp/Grpc.Examples.Tests/MathClientServerTests.cs
@@ -37,7 +37,7 @@
         Channel channel;
         Math.MathClient client;
 
-        [TestFixtureSetUp]
+        [OneTimeSetUp]
         public void Init()
         {
             // Disable SO_REUSEPORT to prevent https://github.com/grpc/grpc/issues/10755
@@ -51,7 +51,7 @@
             client = new Math.MathClient(channel);
         }
 
-        [TestFixtureTearDown]
+        [OneTimeTearDown]
         public void Cleanup()
         {
             channel.ShutdownAsync().Wait();
@@ -130,7 +130,7 @@
         }
 
         [Test]
-        public async Task FibWithDeadline()
+        public void FibWithDeadline()
         {
             using (var call = client.Fib(new FibArgs { Limit = 0 }, 
                 deadline: DateTime.UtcNow.AddMilliseconds(500)))
diff --git a/src/csharp/Grpc.Examples/Grpc.Examples.csproj b/src/csharp/Grpc.Examples/Grpc.Examples.csproj
index 625c172..491d313 100755
--- a/src/csharp/Grpc.Examples/Grpc.Examples.csproj
+++ b/src/csharp/Grpc.Examples/Grpc.Examples.csproj
@@ -8,6 +8,7 @@
     <AssemblyName>Grpc.Examples</AssemblyName>
     <PackageId>Grpc.Examples</PackageId>
     <RuntimeFrameworkVersion Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">1.0.4</RuntimeFrameworkVersion>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/csharp/Grpc.Examples/MathServiceImpl.cs b/src/csharp/Grpc.Examples/MathServiceImpl.cs
index 85b5e2d..0cc1b79 100644
--- a/src/csharp/Grpc.Examples/MathServiceImpl.cs
+++ b/src/csharp/Grpc.Examples/MathServiceImpl.cs
@@ -52,9 +52,10 @@
         public override async Task<Num> Sum(IAsyncStreamReader<Num> requestStream, ServerCallContext context)
         {
             long sum = 0;
-            await requestStream.ForEachAsync(async num =>
+            await requestStream.ForEachAsync(num =>
             {
                 sum += num.Num_;
+                return TaskUtils.CompletedTask;
             });
             return new Num { Num_ = sum };
         }
diff --git a/src/csharp/Grpc.HealthCheck.Tests/Grpc.HealthCheck.Tests.csproj b/src/csharp/Grpc.HealthCheck.Tests/Grpc.HealthCheck.Tests.csproj
index b0e2716..2ccf46b 100755
--- a/src/csharp/Grpc.HealthCheck.Tests/Grpc.HealthCheck.Tests.csproj
+++ b/src/csharp/Grpc.HealthCheck.Tests/Grpc.HealthCheck.Tests.csproj
@@ -10,6 +10,7 @@
     <PackageId>Grpc.HealthCheck.Tests</PackageId>
     <PackageTargetFallback Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">$(PackageTargetFallback);portable-net45</PackageTargetFallback>
     <RuntimeFrameworkVersion Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">1.0.4</RuntimeFrameworkVersion>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/csharp/Grpc.HealthCheck.Tests/HealthClientServerTest.cs b/src/csharp/Grpc.HealthCheck.Tests/HealthClientServerTest.cs
index 7dadba7..45e8ad9 100644
--- a/src/csharp/Grpc.HealthCheck.Tests/HealthClientServerTest.cs
+++ b/src/csharp/Grpc.HealthCheck.Tests/HealthClientServerTest.cs
@@ -37,7 +37,7 @@
         Grpc.Health.V1.Health.HealthClient client;
         Grpc.HealthCheck.HealthServiceImpl serviceImpl;
 
-        [TestFixtureSetUp]
+        [OneTimeSetUp]
         public void Init()
         {
             serviceImpl = new HealthServiceImpl();
@@ -54,7 +54,7 @@
             client = new Grpc.Health.V1.Health.HealthClient(channel);
         }
 
-        [TestFixtureTearDown]
+        [OneTimeTearDown]
         public void Cleanup()
         {
             channel.ShutdownAsync().Wait();
diff --git a/src/csharp/Grpc.Microbenchmarks/Grpc.Microbenchmarks.csproj b/src/csharp/Grpc.Microbenchmarks/Grpc.Microbenchmarks.csproj
index 26a940e..17797e1 100644
--- a/src/csharp/Grpc.Microbenchmarks/Grpc.Microbenchmarks.csproj
+++ b/src/csharp/Grpc.Microbenchmarks/Grpc.Microbenchmarks.csproj
@@ -10,6 +10,7 @@
     <PackageId>Grpc.Microbenchmarks</PackageId>
     <PackageTargetFallback Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">$(PackageTargetFallback);portable-net45</PackageTargetFallback>
     <RuntimeFrameworkVersion Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">1.0.4</RuntimeFrameworkVersion>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/csharp/Grpc.Reflection.Tests/Grpc.Reflection.Tests.csproj b/src/csharp/Grpc.Reflection.Tests/Grpc.Reflection.Tests.csproj
index af6ade8..cf756c6 100755
--- a/src/csharp/Grpc.Reflection.Tests/Grpc.Reflection.Tests.csproj
+++ b/src/csharp/Grpc.Reflection.Tests/Grpc.Reflection.Tests.csproj
@@ -10,6 +10,7 @@
     <PackageId>Grpc.Reflection.Tests</PackageId>
     <PackageTargetFallback Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">$(PackageTargetFallback);portable-net45</PackageTargetFallback>
     <RuntimeFrameworkVersion Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">1.0.4</RuntimeFrameworkVersion>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/csharp/Grpc.Reflection.Tests/ReflectionClientServerTest.cs b/src/csharp/Grpc.Reflection.Tests/ReflectionClientServerTest.cs
index 7e894ed..76f8cfa 100644
--- a/src/csharp/Grpc.Reflection.Tests/ReflectionClientServerTest.cs
+++ b/src/csharp/Grpc.Reflection.Tests/ReflectionClientServerTest.cs
@@ -38,7 +38,7 @@
         ServerReflection.ServerReflectionClient client;
         ReflectionServiceImpl serviceImpl;
 
-        [TestFixtureSetUp]
+        [OneTimeSetUp]
         public void Init()
         {
             serviceImpl = new ReflectionServiceImpl(ServerReflection.Descriptor);
@@ -55,7 +55,7 @@
             client = new ServerReflection.ServerReflectionClient(channel);
         }
 
-        [TestFixtureTearDown]
+        [OneTimeTearDown]
         public void Cleanup()
         {
             channel.ShutdownAsync().Wait();