Project Setup

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>net5.0</TargetFramework>
    <!-- ... -->
    <!-- mandatory nullable typing -->
    <Nullable>enable</Nullable>
    <LangVersion>9.0</LangVersion>
    <WarningsAsErrors>CS8618;CS8765;CS8625;CS8603;CS8602;CS8600;CS8604;CS8622;CS8620</WarningsAsErrors>
    <!-- ... -->
  </PropertyGroup>
</Project>