a simple parser for URL
``` rust fn main(){ let mockurl = "https://lb:123456@www.google.com:123/blog/01?a=1&b=2#132456"; let urlobj = URL::parse(mock_url).unwrap();
assert_eq!(url_obj.scheme, "https:");
assert_eq!(url_obj.username, "lb");
assert_eq!(url_obj.password, "123456");
assert_eq!(url_obj.host, "www.google.com");
assert_eq!(url_obj.port, "123");
assert_eq!(url_obj.path, "/blog/01");
assert_eq!(url_obj.query, "?a=1&b=2");
assert_eq!(url_obj.hash, "#132456");
let url_str = URL::stringify(&url_obj);
assert_eq!(url_str, mock_url);
} ```