Use the new Nodes class for a better test

src/Node/SetNode.php

@@ -33,7 +33,8 @@ public function __construct(bool $capture, Node $names, Node $values, int $linen
         $safe = false;
         if ($capture) {
             $safe = true;
-            if (Node::class === get_class($values) && !count($values)) {
+            // The second part of the condition should be removed in Twig 4.0
+            if ($values instanceof Nodes && !count($values) || Node::class === get_class($values)) {
                 $values = new ConstantExpression('', $values->getTemplateLine());
                 $capture = false;
             } elseif ($values instanceof TextNode) {

src/Parser.php

@@ -373,7 +373,8 @@ private function filterBodyNodes(Node $node, bool $nested = false): ?Node
 
         // here, $nested means "being at the root level of a child template"
         // we need to discard the wrapping "Node" for the "body" node
-        $nested = $nested || Nodes::class !== \get_class($node);
+        // The second part of the condition should be removed in Twig 4.0
+        $nested = $nested || $node instanceof Nodes || Node::class !== \get_class($node);
         foreach ($node as $k => $n) {
             if (null !== $n && null === $this->filterBodyNodes($n, $nested)) {
                 $node->removeNode($k);