`Message` implements both `InputStream`_and_`Promise`. This allows consuming a message either in chunks (streaming) or consume everything at once (buffering).
## Buffering
Buffering a complete input stream is quite easy, you can simply `yield` a `Message` just like any other `Promise`. If you have an `InputStream` that's not a `Message`, simply create a new instance from it using `new Message($inputStream)`.
```php
$message = new Message($inputStream);
$content = yield $message;
```
## Streaming
Sometimes it's useful / possible to consume a message in chunks rather than first buffering it completely. An example might be streaming a large HTTP response body directly to disk.
```php
while (($chunk = yield $message->read()) !== null) {
// Use $chunk here, works just like any other InputStream
}
```
## Unwrapping
In some cases you might want to resolve a promise with an `InputStream` or your method explicitly declares `InputStream` as a return type. In these cases you should use `Message::getInputStream` to return the raw input stream. This makes it possible to resolve promises with the `InputStream` and not run into unexpected issues. Only return a `Message` if you declare that as a type, otherwise an API assumes `InputStream` and might try to resolve a promise with that, resulting in buffering the message's content instead of resolving the promise with an `InputStream` instance.
