<PackageReference Include="Microsoft.Bcl.Cryptography" Version="11.0.0-rc.1.26425.128" />

System.Diagnostics.CodeAnalysis.MemberNotNullWhenAttribute

Specifies that the method or property will ensure that the listed field and property members have not-null values when returning with the specified return value condition.
namespace System.Diagnostics.CodeAnalysis { } namespace System.Diagnostics.CodeAnalysis { }