Proxy\Proxy::write_callback PHP Method

    private function write_callback($ch, $str)
    {
        $len = strlen($str);
        $this->dispatcher->dispatch('curl.callback.write', new ProxyEvent(array('request' => $this->request, 'data' => $str)));
        // Do we buffer this piece of data for later output or not?
        if ($this->output_buffering) {
            $this->output_buffer .= $str;
        }
        return $len;
    }