<PackageReference Include="Microsoft.Extensions.FileProviders.Abstractions" Version="11.0.0-rc.1.26425.128" />

System.Diagnostics.CodeAnalysis.NotNullWhenAttribute

Specifies that when a method returns ReturnValue, the parameter will not be null even if the corresponding type allows it.
namespace System.Diagnostics.CodeAnalysis { } namespace System.Diagnostics.CodeAnalysis { } namespace System.Diagnostics.CodeAnalysis { } namespace System.Diagnostics.CodeAnalysis { }