public function sendHeader()
    {
        $file = $line = null;
        if ($this->isHeaderSent($file, $line)) {
            if ($this->wei->has('logger')) {
                $this->logger->debug(sprintf('Header has been at %s:%s', $file, $line));
            }
            return false;
        }

        // Send status
        $this->sendRawHeader(sprintf('HTTP/%s %d %s', $this->version, $this->statusCode, $this->statusText));

        // Send headers
        foreach ($this->headers as $name => $values) {
            foreach ($values as $value) {
                $this->sendRawHeader($name . ': ' . $value);
            }
        }

        $this->sendCookie();

        return true;
    }