// Hostnames - should remain unchanged
        assertEquals("localhost", IpAddressUtil.formatForUrl("localhost"));
        assertEquals("example.com", IpAddressUtil.formatForUrl("example.com"));

        // Null
        assertNull(IpAddressUtil.formatForUrl(null));
    }

    @Test
    public void testGetUrlHost() throws UnknownHostException {
        // IPv4 localhost

    "output": "ab--c.xn--zca"
  },
  {
    "input": "ab--c.ß",
    "output": "ab--c.xn--zca"
  },
  {
    "comment": "CheckJoiners is true",
    "input": "\u200D.example",
    "output": null
  },
  {
    "input": "xn--1ug.example",
    "output": null
  },
  {
    "comment": "CheckBidi is true",
    "input": "يa",
    "output": null
  },
  {
    "input": "xn--a-yoc",
    "output": null

For example, you can raise a different exception, like `HTTPException`.

/// tip

This is a somewhat advanced technique, and in most of the cases you won't really need it, as you can raise exceptions (including `HTTPException`) from inside of the rest of your application code, for example, in the *path operation function*.

But it's there for you if you need it. 🤓

 * shared resources.
 *
 * @param <K> the most general type of keys this listener can listen for; for example {@code Object}
 *     if any key is acceptable
 * @param <V> the most general type of values this listener can listen for; for example {@code
 *     Object} if any key is acceptable
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
@FunctionalInterface

If you want to return additional status codes apart from the main one, you can do that by returning a `Response` directly, like a `JSONResponse`, and set the additional status code directly.

For example, let's say that you want to have a *path operation* that allows to update items, and returns HTTP status codes of 200 "OK" when successful.

 * interfere with session-based authentication schemes that require cookies.
 *
 * As persistence, implementations of this interface must also provide storage of cookies. Simple
 * implementations may store cookies in memory; sophisticated ones may use the file system or
 * database to hold accepted cookies. The [cookie storage model][rfc_6265_53] specifies policies for
 * updating and expiring cookies.

      // OkHttp doesn't reject U+FFFD encoded in Punycode.
      "xn--zn7c.com",
      // OkHttp doesn't reject a U+200D. https://www.rfc-editor.org/rfc/rfc5892.html#appendix-A.2
      "xn--1ug.example",
      // OkHttp doesn't implement CheckJoiners.
      "\u200D.example",
      // OkHttp doesn't implement CheckBidi.
      "يa",
    )

  @Test
  fun test() {
    val list = WebPlatformToAsciiData.load()

If a client tries to send some **extra** data in the **query parameters**, they will receive an **error** response.

For example, if the client tries to send a `tool` query parameter with a value of `plumbus`, like:

```http
https://example.com/items/?limit=10&tool=plumbus
```

They will receive an **error** response telling them that the query parameter `tool` is not allowed:

```json
{

            "servers": [
                {"url": "/api/v1"},
                {
                    "url": "https://stag.example.com",
                    "description": "Staging environment",
                },
                {
                    "url": "https://prod.example.com",
                    "description": "Production environment",
                },
            ],
            "paths": {

    }

    @Test
    public void test_user_mail() {
        final User user = new User();
        assertNull(user.getMail());

        user.setMail("test@example.com");
        assertEquals("test@example.com", user.getMail());
    }

    @Test
    public void test_user_telephoneNumber() {
        final User user = new User();
        assertNull(user.getTelephoneNumber());