public static ITypeSignature GetDeclaringType(this ITypeSignature typeSig)
        {
            typeSig = typeSig.GetLastElementType();
            if (typeSig.ElementCode == TypeElementCode.GenericType)
            {
                typeSig = typeSig.DeclaringType;
            }

            if (typeSig.ElementCode == TypeElementCode.DeclaringType)
            {
                return(typeSig);
            }

            return(null);
        }