public function displayHelp() {
        $string = 'Using: ' . $this->script . ' ' . $this->command . ' ';
        $where = array();
        foreach ($this->parameters as $Option) {
            /** @var $Option Option */
            $short = $Option->getShort();
            $long = $Option->getLong();
            $temp = '-' . $short . '|--' . $long;
            if (!$Option->isRequired()) {
                $string .= '[' . $temp . '] ';
            } else {
                $string .= $temp . ' ';
            }

            $where[] = '-' . $short . ', --' . $long . '  - ' . $Option->getDescription();
        }
        $string .= "\n";
        $string .= implode("\n", $where) . "\n";
        echo $string;
        exit(0);
    }