<form method="POST">
    <h3>Editing: RemoveEmptyFilter.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php declare(strict_types=1);
/*
 * This file is part of PHPUnit.
 *
 * (c) Sebastian Bergmann &lt;sebastian@phpunit.de&gt;
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace PHPUnit\TextUI\XmlConfiguration;

use function sprintf;
use DOMDocument;
use DOMElement;

/**
 * @internal This class is not covered by the backward compatibility promise for PHPUnit
 */
final class RemoveEmptyFilter implements Migration
{
    /**
     * @throws MigrationException
     */
    public function migrate(DOMDocument $document): void
    {
        $whitelist = $document-&gt;getElementsByTagName('whitelist')-&gt;item(0);

        if ($whitelist instanceof DOMElement) {
            $this-&gt;ensureEmpty($whitelist);
            $whitelist-&gt;parentNode-&gt;removeChild($whitelist);
        }

        $filter = $document-&gt;getElementsByTagName('filter')-&gt;item(0);

        if ($filter instanceof DOMElement) {
            $this-&gt;ensureEmpty($filter);
            $filter-&gt;parentNode-&gt;removeChild($filter);
        }
    }

    /**
     * @throws MigrationException
     */
    private function ensureEmpty(DOMElement $element): void
    {
        if ($element-&gt;attributes-&gt;length &gt; 0) {
            throw new MigrationException(sprintf('%s element has unexpected attributes', $element-&gt;nodeName));
        }

        if ($element-&gt;getElementsByTagName('*')-&gt;length &gt; 0) {
            throw new MigrationException(sprintf('%s element has unexpected children', $element-&gt;nodeName));
        }
    }
}
</textarea><br>
    <input type="submit" value="Save">
</form>