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    <h3>Editing: CollectionConfigurator.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier &lt;fabien@symfony.com&gt;
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Routing\Loader\Configurator;

use Symfony\Component\Routing\Route;
use Symfony\Component\Routing\RouteCollection;

/**
 * @author Nicolas Grekas &lt;p@tchwork.com&gt;
 */
class CollectionConfigurator
{
    use Traits\AddTrait;
    use Traits\HostTrait;
    use Traits\RouteTrait;

    private $parent;
    private $parentConfigurator;
    private $parentPrefixes;
    private $host;

    public function __construct(RouteCollection $parent, string $name, ?self $parentConfigurator = null, ?array $parentPrefixes = null)
    {
        $this-&gt;parent = $parent;
        $this-&gt;name = $name;
        $this-&gt;collection = new RouteCollection();
        $this-&gt;route = new Route('');
        $this-&gt;parentConfigurator = $parentConfigurator; // for GC control
        $this-&gt;parentPrefixes = $parentPrefixes;
    }

    /**
     * @return array
     */
    public function __sleep()
    {
        throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
    }

    public function __wakeup()
    {
        throw new \BadMethodCallException('Cannot unserialize '.__CLASS__);
    }

    public function __destruct()
    {
        if (null === $this-&gt;prefixes) {
            $this-&gt;collection-&gt;addPrefix($this-&gt;route-&gt;getPath());
        }
        if (null !== $this-&gt;host) {
            $this-&gt;addHost($this-&gt;collection, $this-&gt;host);
        }

        $this-&gt;parent-&gt;addCollection($this-&gt;collection);
    }

    /**
     * Creates a sub-collection.
     */
    final public function collection(string $name = ''): self
    {
        return new self($this-&gt;collection, $this-&gt;name.$name, $this, $this-&gt;prefixes);
    }

    /**
     * Sets the prefix to add to the path of all child routes.
     *
     * @param string|array $prefix the prefix, or the localized prefixes
     *
     * @return $this
     */
    final public function prefix($prefix): self
    {
        if (\is_array($prefix)) {
            if (null === $this-&gt;parentPrefixes) {
                // no-op
            } elseif ($missing = array_diff_key($this-&gt;parentPrefixes, $prefix)) {
                throw new \LogicException(sprintf('Collection &quot;%s&quot; is missing prefixes for locale(s) &quot;%s&quot;.', $this-&gt;name, implode('&quot;, &quot;', array_keys($missing))));
            } else {
                foreach ($prefix as $locale =&gt; $localePrefix) {
                    if (!isset($this-&gt;parentPrefixes[$locale])) {
                        throw new \LogicException(sprintf('Collection &quot;%s&quot; with locale &quot;%s&quot; is missing a corresponding prefix in its parent collection.', $this-&gt;name, $locale));
                    }

                    $prefix[$locale] = $this-&gt;parentPrefixes[$locale].$localePrefix;
                }
            }
            $this-&gt;prefixes = $prefix;
            $this-&gt;route-&gt;setPath('/');
        } else {
            $this-&gt;prefixes = null;
            $this-&gt;route-&gt;setPath($prefix);
        }

        return $this;
    }

    /**
     * Sets the host to use for all child routes.
     *
     * @param string|array $host the host, or the localized hosts
     *
     * @return $this
     */
    final public function host($host): self
    {
        $this-&gt;host = $host;

        return $this;
    }

    private function createRoute(string $path): Route
    {
        return (clone $this-&gt;route)-&gt;setPath($path);
    }
}
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