public function dump(ServerInterface $server, $spaces = 0)
    {
        $config = '';

        foreach ($this->directives as $directive) {
            $config .= $directive->dump($server, $spaces + ($this->isMainContext() ? 0 : 4));
        }

        return $this->dumpBlock($server->getDumperStartDirective(), $spaces).
            $config.
            $this->dumpBlock($server->getDumperEndDirective(), $spaces);
    }