public function checkCompressionSettings($settings)
    {
        $errors = array();

        if (isset($settings['compress'])) {
            if (!is_array($settings['compress'])) {
                $errors[] = "invalid_syntax";
            } else if (isset($settings['compress']['requests'])
                && $settings['compress']['requests'] !== true
                && $settings['compress']['requests'] !== false
            ) {
                $errors[] = "'compress'=>'requests' values must be true or false.";
            } else if (isset($settings['compress']['responses'])
                && $settings['compress']['responses'] !== true
                && $settings['compress']['responses'] !== false
            ) {
                $errors[] = "'compress'=>'responses' values must be true or false.";
            }
        }
        return $errors;
    }