code: func ApplicationNew(appId string, flags glib.ApplicationFlags) (*Application, error) {
  	cstr := (*C.gchar)(C.CString(appId))
  	defer C.free(unsafe.Pointer(cstr))
  
  	c := C.gtk_application_new(cstr, C.GApplicationFlags(flags))
  	if c == nil {
  		return nil, nilPtrErr
  	}
  	return wrapApplication(glib.Take(unsafe.Pointer(c))), nil
  }
docs: // ApplicationNew is a wrapper around gtk_application_new().