* `URL` {URL} A [WHATWG URL][] object

* `options` {Object}

* `auth` {boolean} `true` if the serialized URL string should include the

username and password, `false` otherwise. Defaults to `true`.

* `fragment` {boolean} `true` if the serialized URL string should include the

fragment, `false` otherwise. Defaults to `true`.

* `search` {boolean} `true` if the serialized URL string should include the

search query, `false` otherwise. Defaults to `true`.

* `unicode` {boolean} `true` if Unicode characters appearing in the host

component of the URL string should be encoded directly as opposed to being

Punycode encoded. Defaults to `false`.

Returns a customizable serialization of a URL String representation of a

[WHATWG URL][] object.

The URL object has both a `toString()` method and `href` property that return

string serializations of the URL. These are not, however, customizable in

any way. The `url.format(URL[, options])` method allows for basic customization

of the output.

For example:

const myURL = new URL('https://a:b@你好你好?abc#foo');

console.log(myURL.href);

// Prints https://a:b@xn--6qqa088eba/?abc#foo

console.log(myURL.toString());

// Prints https://a:b@xn--6qqa088eba/?abc#foo

console.log(url.format(myURL, {fragment: false, unicode: true, auth: false}));

// Prints 'https://你好你好?abc'

*Note*: This variation of the `url.format()` method is currently considered to

be experimental.