assertInvalid("http://\uDBFF\uDFFF", "Invalid URL host: \"\uDBFF\uDFFF\"")
  }

  @Test
  fun hostnameUri() {
    // Host names are special:
    //
    //  * Several characters are forbidden and must throw exceptions if used.
    //  * They don't use percent escaping at all.
    //  * They use punycode for internationalization.

 *  **Canceling batches of calls is now the application's responsibility.**
    The API to cancel calls by tag has been removed and replaced with a more
    general mechanism. The dispatcher now exposes all in-flight calls via its
    `runningCalls()` and `queuedCalls()` methods. You can write code that
    selects calls by tag, host, or whatever, and invokes `Call.cancel()` on the

   * consulting the [public suffix list](https://publicsuffix.org). Returns null if this URL's
   * [host] is an IP address or is considered a public suffix by the public suffix list.
   *
   * In general this method **should not** be used to test whether a domain is valid or routable.
   * Instead, DNS is the recommended source for that information.
   *
   * | URL                           | `topPrivateDomain()` |