public function usageHelp()
    {
        $help = 'Available actions: ' . "\n";
        $methods = get_class_methods($this);
        foreach ($methods as $method) {
            if (substr($method, -6) == 'Action') {
                $help .= '    --action ' . substr($method, 0, -6);
                $helpMethod = $method . 'Help';
                if (method_exists($this, $helpMethod)) {
                    $help .= ' ' . $this->$helpMethod();
                }
                $help .= "\n";
            }
        }
        return $help;
    }