System.Net.Http.WinHttpHandler.csproj

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppPrevious);$(NetCoreAppMinimum);netstandard2.1;netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
  </PropertyGroup>

  <ItemGroup>
    <Compile Include="System.Net.Http.WinHttpHandler.cs" />
  </ItemGroup>

  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">
    <Reference Include="System.Net.Http" />
  </ItemGroup>
</Project>