A source code only package which allows you to use .NET's nullable attributes in older target frameworks like .NET Standard 2.0 or the "old" .NET Framework.
[x] They are available in a .NET release/are finalized and no longer prone to change.
[x] It is verified that the compiler also supports them when they are declared as internal attributes (otherwise adding them to this package has no benefit).
New nullability attributes are currently being introduced (see https://github.com/dotnet/runtime/blob/master/src/libraries/System.Private.CoreLib/src/System/Diagnostics/CodeAnalysis/NullableAttributes.cs).
These should be added to Nullable as soon as:
internal
attributes (otherwise adding them to this package has no benefit).