public static T _ <T>(this go.encoding.xml_package.Marshaler target) { try { return(((go.encoding.xml_package.Marshaler <T>)target).Target); } catch (NotImplementedException ex) { throw new PanicException($"interface conversion: {GetGoTypeName(target.GetType())} is not {GetGoTypeName(typeof(T))}: missing method {ex.InnerException?.Message}"); } }