Icicle\Http\Driver\Encoder\Http1Encoder::encodeHeaders PHP Method

    protected function encodeHeaders(array $headers) : string
    {
        $data = '';
        foreach ($headers as $name => $values) {
            foreach ($values as $value) {
                $data .= sprintf("%s: %s\r\n", $name, $this->encodeHeader($value));
            }
        }
        return $data;
    }