Aerys\Body::__construct PHP Method

    public function __construct(Promise $promise)
    {
        $promise->watch(function ($data) {
            foreach ($this->watchers as list($func, $cbData)) {
                $func($data, $cbData);
            }
        });
        parent::__construct($promise);
        // DO NOT MOVE - preserve order in which things happen
        $when = function ($e, $bool) use(&$continue) {
            $continue = $bool;
        };
        $promise->when(function () use(&$continue, $when) {
            $this->valid()->when($when);
            while ($continue) {
                $string[] = $this->consume();
                $this->valid()->when($when);
            }
            $this->valid()->when(function ($ex) use(&$e) {
                $e = $ex;
            });
            if (isset($string)) {
                if (isset($string[1])) {
                    $string = implode($string);
                } else {
                    $string = $string[0];
                }
                // way to restart, so that even after the success, the valid() / consume() API will still work
                if (!$e) {
                    $result = $this->consume();
                    // consume the final result
                }
                $deferred = new \Amp\Deferred();
                parent::__construct($deferred->promise());
                $deferred->update($string);
                if ($e) {
                    $deferred->fail($e);
                } else {
                    $deferred->succeed($result);
                }
            } else {
                $string = "";
            }
            $this->string = $string;
            $this->error = $e;
            foreach ($this->whens as list($when, $data)) {
                $when($e, $string, $data);
            }
            $this->whens = $this->watchers = [];
        });
    }

 public function __construct(Promise $promise, Promise $metadata)
 {
     parent::__construct($promise);
     $this->metadata = $metadata;
     $this->valid = $this->valid();
 }