public static bool Is7 <T1, T2, T3, T4, T5, T6, T7, T8>(this IOrType <T1, T2, T3, T4, T5, T6, T7, T8> self, out T7 t7) { if (self.Possibly7() is IIsDefinately <T7> definate) { t7 = definate.Value; return(true); } t7 = default; return(false); }