Whenever the page sends a request, such as for a network resource, the following events are emitted by Puppeteer's `page`<!-- -->:
-`request`<!-- -->: emitted when the request is issued by the page. - `requestfinished` - emitted when the response body is downloaded and the request is complete.
If request fails at some point, then instead of `requestfinished` event the `requestfailed` event is emitted.
All of these events provide an instance of `HTTPRequest` representing the request that occurred:
```
page.on('request', request => ...)
```
NOTE: HTTP Error responses, such as 404 or 503, are still successful responses from HTTP standpoint, so request will complete with `requestfinished` event.
If request gets a 'redirect' response, the request is successfully finished with the `requestfinished` event, and a new request is issued to a redirected url.
The constructor for this class is marked as internal. Third-party code should not call the constructor directly or create subclasses that extend the `HTTPRequest` class.
