code: func ImageNewFromFile(filename string) (*Image, error) {
  	cstr := C.CString(filename)
  	defer C.free(unsafe.Pointer(cstr))
  	c := C.gtk_image_new_from_file((*C.gchar)(cstr))
  	if c == nil {
  		return nil, nilPtrErr
  	}
  	obj := glib.Take(unsafe.Pointer(c))
  	return wrapImage(obj), nil
  }
docs: // ImageNewFromFile() is a wrapper around gtk_image_new_from_file().