PHPDaemon\Clients\HTTP\Pool::head PHP Method

    public function head($url, $params)
    {
        if (is_callable($params)) {
            $params = ['resultcb' => $params];
        }
        if (!isset($params['uri']) || !isset($params['host'])) {
            list($params['scheme'], $params['host'], $params['uri'], $params['port']) = static::parseUrl($url);
        }
        if (isset($params['connect'])) {
            $dest = $params['connect'];
        } elseif (isset($params['proxy']) && $params['proxy']) {
            if ($params['proxy']['type'] === 'http') {
                $dest = 'tcp://' . $params['proxy']['addr'];
            }
        } else {
            $dest = 'tcp://' . $params['host'] . (isset($params['port']) ? ':' . $params['port'] : null) . ($params['scheme'] === 'https' ? '#ssl' : '');
        }
        $this->getConnection($dest, function ($conn) use($url, $params) {
            if (!$conn->isConnected()) {
                $params['resultcb'](false);
                return;
            }
            $conn->head($url, $params);
        });
    }