Nats\Connection::receive PHP Method

    private function receive($len = null)
    {
        if ($len) {
            $chunkSize = $this->chunkSize;
            $line = null;
            $receivedBytes = 0;
            while ($receivedBytes < $len) {
                $bytesLeft = $len - $receivedBytes;
                if ($bytesLeft < $this->chunkSize) {
                    $chunkSize = $bytesLeft;
                }
                $readChunk = fread($this->streamSocket, $chunkSize);
                $receivedBytes += strlen($readChunk);
                $line .= $readChunk;
            }
        } else {
            $line = fgets($this->streamSocket);
        }
        return $line;
    }