// http://example.org/path?q=dart.
Uri.http("example.org", "/path", { "q" : "dart" });

// http://user:pass@localhost:8080
Uri.http("user:pass@localhost:8080", "");

// http://example.org/a%20b
Uri.http("example.org", "a b");

// http://example.org/a%252F
Uri.http("example.org", "/a%2F");