Ch 20 Listings: 14,15,16 are not compiling.
MODIFY
src/Chapter20/Chapter20.csproj
src/Chapter20/Chapter20.csproj
<ItemGroup>
<Compile Remove="Listing20.07.SignaturesOfAsyncEnumerableSelectMethods.cs" />
<Compile Remove="Listing20.13.SynchronousHighLatencyInvocationInWPF.cs" />
+ <Compile Remove="Listing20.14.SynchronousHighLatencyInvocationInWPF.cs" />
<Compile Remove="Listing20.14.SynchronousHighLatencyInvocationInWPFUsingAwait.cs" />
<Compile Remove="Listing20.15.IteratingOverAwaitOperation.cs" />
+ <Compile Remove="Listing20.15.SynchronousHighLatencyInvocationInWPFUsingAwait.cs" />
+ <Compile Remove="Listing20.16.IteratingOverAwaitOperation.cs" />
</ItemGroup>
<ItemGroup>
<Compile Include="..\Shared\Program.cs">
</Compile>
<None Include="Listing20.07.SignaturesOfAsyncEnumerableSelectMethods.cs" />
<None Include="Listing20.13.SynchronousHighLatencyInvocationInWPF.cs" />
+ <None Include="Listing20.14.SynchronousHighLatencyInvocationInWPF.cs" />
<None Include="Listing20.14.SynchronousHighLatencyInvocationInWPFUsingAwait.cs" />
<None Include="Listing20.15.IteratingOverAwaitOperation.cs" />
+ <None Include="Listing20.15.SynchronousHighLatencyInvocationInWPFUsingAwait.cs" />
+ <None Include="Listing20.16.IteratingOverAwaitOperation.cs" />
<PackageReference Include="System.Linq.Async" Version="4.0.0" />
</ItemGroup>
</Project>

Ch 20 Listings: 14,15,16 are not compiling.