Don't use a new document when importing nodes

Author: tvdijen

src/AbstractElement.php

@@ -153,10 +153,10 @@ public static function getChildrenOfClass(DOMElement $parent): array
                 && $node->namespaceURI === static::getNamespaceURI()
                 && $node->localName === static::getLocalName()
             ) {
-                // Normalize the DOMElement by importing it into a clean empty document
-                $newDoc = DOMDocumentFactory::create();
                 /** @var \DOMElement $node */
-                $node = $newDoc->appendChild($newDoc->importNode($node, true));
+                $node = $parent->ownerDocument->appendChild(
+                    $parent->ownerDocument->importNode($node, true),
+                );
 
                 $ret[] = static::fromXML($node);
             }