@Override
    public String toString() {
        return this.toURI().toString();
    }
@Test
    void testToString() {
        assertEquals("//127.0.0.1:8080", new Proxy("127.0.0.1", 8080).toString());
        assertEquals("http://127.0.0.1:8080", new Proxy("127.0.0.1", 8080, "http").toString());
        assertEquals("//username:password@127.0.0.1:8080", new Proxy("127.0.0.1", 8080, "username", "password").toString());
        assertEquals("//username@127.0.0.1:8080", new Proxy("127.0.0.1", 8080, "username", null).toString());
        assertEquals("//:password@127.0.0.1:8080", new Proxy("127.0.0.1", 8080, null, "password").toString());
    }