Vcr-sharp lets you record and playback HTTP requests! In this example, WithCassette is an extension method on HttpClientFactory. That extension method sets up a DelgatingHandler to a ReplayingHandler. That ReplayingHandler "loads the cassette" and returns it as a cached response. 

  using (var httpClient = HttpClientFactory.WithCassette( "my-test-scenario" ))      
  {        
    var request =  new HttpRequestMessage(HttpMethod.Get,  "http://www.iana.org/domains/reserved" );   
    var response = await httpClient.SendAsync(request);     
    var body = await response.Content.ReadAsStringAsync();      
    body.ShouldContain( "Example domains" );     
  }

Ever since Microsoft purchased GitHub, many people have been searching for alternative places to host and share their code.

Microsoft Just Bought GitHub: Pros, Cons, and What It Means for You

Though Apple servers are widely believed to be unhackable, a 16-year-old high school student proved that nothing is impossible

Everywhere the problem to this solution was mentioned as re-registering aspNet by using aspnet_regiis.exe. But this did not work for me.
Though this is a valid solution (as explained beautifully here)
but it did not work with Windows 8.
For Windows 8 you need to Windows features and enable everything under ".Net Framework 3.5" and ".Net Framework 4.5 Advanced Services".

The C# Dev Kit leverages the core C# language services and delivers additional productivity value to developers. 

Mercury is currently 99.9% compatible with Visual Basic.NET, and already adds a wide range of language extensions and support for C# 9.0 features that will make the VB developers lives easier. The extras include support for pointers and unsafe code, lazy properties, and C# 9's new records. 

C♯ is C++ with more safety features so that ordinary civilians can use it. It looks kind of silly but it has most of the same power so long as you stay near gas pumps and auto shops and the comforts of civilization. A well-known heavily muscular intimidator keeps touting it.