Aerys\BodyParser::end PHP Method

    private function end($data)
    {
        if (!$this->bodies && $data != "") {
            // if we end up here, we haven't parsed anything at all yet, so do a quick parse
            if ($this->boundary !== null) {
                $fields = $metadata = [];
                // RFC 7578, RFC 2046 Section 5.1.1
                if (strncmp($data, "--{$this->boundary}\r\n", \strlen($this->boundary) + 4) !== 0) {
                    return new ParsedBody([]);
                }
                $exp = explode("\r\n--{$this->boundary}\r\n", $data);
                $exp[0] = substr($exp[0], \strlen($this->boundary) + 4);
                $exp[count($exp) - 1] = substr(end($exp), 0, -\strlen($this->boundary) - 8);
                foreach ($exp as $entry) {
                    list($rawheaders, $text) = explode("\r\n\r\n", $entry, 2);
                    $headers = [];
                    foreach (explode("\r\n", $rawheaders) as $header) {
                        $split = explode(":", $header, 2);
                        if (!isset($split[1])) {
                            return new ParsedBody([]);
                        }
                        $headers[strtolower($split[0])] = trim($split[1]);
                    }
                    if (!preg_match('#^\\s*form-data(?:\\s*;\\s*(?:name\\s*=\\s*"([^"]+)"|filename\\s*=\\s*"([^"]+)"))+\\s*$#', $headers["content-disposition"] ?? "", $m) || !isset($m[1])) {
                        return new ParsedBody([]);
                    }
                    $name = $m[1];
                    $fields[$name][] = $text;
                    // Ignore Content-Transfer-Encoding as deprecated and hence we won't support it
                    if (isset($m[2])) {
                        $metadata[$name][count($fields[$name]) - 1] = ["filename" => $m[2], "mime" => $headers["content-type"] ?? "application/octet-stream"];
                    } elseif (isset($headers["content-type"])) {
                        $metadata[$name][count($fields[$name]) - 1]["mime"] = $headers["content-type"];
                    }
                }
                return new ParsedBody($fields, $metadata);
            } else {
                $fields = [];
                foreach (explode("&", $data) as $pair) {
                    $pair = explode("=", $pair, 2);
                    $fields[urldecode($pair[0])][] = urldecode($pair[1] ?? "");
                }
                return new ParsedBody($fields, []);
            }
        } else {
            $fields = $metadata = [];
            $when = static function ($e, $data) use(&$fields, &$key) {
                $fields[$key][] = $data;
            };
            $metawhen = static function ($e, $data) use(&$metadata, &$key) {
                $metadata[$key][] = $data;
            };
            foreach ($this->bodies as $key => $bodies) {
                foreach ($bodies as $body) {
                    $body->when($when);
                    $body->getMetadata()->when($metawhen);
                }
                $metadata[$key] = array_filter($metadata[$key]);
            }
            return new ParsedBody($fields, array_filter($metadata));
        }
    }