bool is_url(const char *str);
struct pb_url *pb_url_parse(void *ctx, const char *url_str);
+struct pb_url *pb_url_copy(void *ctx, const struct pb_url *url);
struct pb_url *pb_url_join(void *ctx, const struct pb_url *url, const char *s);
char *pb_url_to_string(struct pb_url *url);