#nullable enable
// Nullable references enabled here
#nullable disable
// Nullable references disabled here
#nullable restore
// Resets status to project settings (i.e. disabled unless <Nullable>enable</Nullable> is specified in csproj, in which case enabled)
// See also https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/preprocessor-directives/preprocessor-nullable