public function core() {
        $key = isset($this->params['key']) ? $this->params['key'] : null;
        $config = isset($this->params['config']) ? $this->params['config'] : 'default';

        if ($key) {
            $this->out(sprintf('Clearing %s in %s...', $key, $config));
            Cache::delete($key, $config);

        } else {
            $this->out(sprintf('Clearing all in %s...', $config));
            Cache::clear(false, $config);
        }

        $this->out('<info>Cache cleared!</info>');
    }