protected function init($id, $file)
    {
        $this->setState(self::RUNNING);
        $this->setId($id);
        $this->setBuffer(array());
        $this->setOutput('');
        $this->setPreviousChar(false);
        $this->setPreviousSignificantChar(false);

        if (($data = @file_get_contents($file)) !== false) {
            $stream = new MemoryStream($data);
            $stream->open();
            $this->setStream($stream);
        } else {
            throw new RenderingException("The CSS file '${file}' could not be open.", RenderingException::RUNTIME);
        }
    }