public static FSharpOption<T> Option`1.filter.Static<T>(FSharpFunc<T, bool> f, FSharpOption<T> x)
{
    FSharpOption<T> option = x;
    if (option != null)
    {
        FSharpOption<T> option2 = option;
        T v = option2.get_Value();
        if (f.Invoke(v))
        {
            return FSharpOption<T>.Some(option2.get_Value());
        }
    }
    return null;
}