private function buildHeaderResponse()
    {
        foreach (explode(
            "\n",
            substr($this->output, 0, $this->info['header_size'])
        ) as $val) {
            $val = trim($val);
            if (! empty($val)) {
                $this->headerResponse[] = $val;
            }
        }
        $this->output = substr($this->output, $this->info['header_size']);
    }