GetFlagEnumValues is not safe to use

[sm-g]

It declares to return IEnumerable<TEnum>, so I except it is never null (https://rules.sonarsource.com/csharp/RSPEC-1168).

But MyEnum.FromValue(0) returns null.

public sealed class MyEnum : SmartFlagEnum<MyEnum>
    {
        public static readonly MyEnum X= new MyEnum(1);
        public static readonly MyEnum Y= new MyEnum(2);

private MyEnum (int value, [CallerMemberName] string name = null)
            : base(name, value)
        {
        }
   }