code: func (v *Pixbuf) GetOption(key string) (value string, ok bool) {
  	cstr := C.CString(key)
  	defer C.free(unsafe.Pointer(cstr))
  	c := C.gdk_pixbuf_get_option(v.native(), (*C.gchar)(cstr))
  	if c == nil {
  		return "", false
  	}
  	return C.GoString((*C.char)(c)), true
  }
docs: // GetOption is a wrapper around gdk_pixbuf_get_option().  ok is true if
  // the key has an associated value.