AssignNameExpression example

// {% stopwatch 'bar' %}         $name = $this->parser->getExpressionParser()->parseExpression();

        $stream->expect(Token::BLOCK_END_TYPE);

        // {% endstopwatch %}         $body = $this->parser->subparse($this->decideStopwatchEnd(...), true);
        $stream->expect(Token::BLOCK_END_TYPE);

        if ($this->stopwatchIsAvailable) {
            return new StopwatchNode($name, $body, new AssignNameExpression($this->parser->getVarName(), $token->getLine()), $lineno, $this->getTag());
        }

        return $body;
    }

    public function decideStopwatchEnd(Token $token): bool
    {
        return $token->test('endstopwatch');
    }

    public function getTag(): string
    {

if ($node instanceof BlockNode || $node instanceof ModuleNode) {
            $this->scope = $this->scope->enter();
        }

        if ($node instanceof TransDefaultDomainNode) {
            if ($node->getNode('expr') instanceof ConstantExpression) {
                $this->scope->set('domain', $node->getNode('expr'));

                return $node;
            } else {
                $var = $this->getVarName();
                $name = new AssignNameExpression($var, $node->getTemplateLine());
                $this->scope->set('domain', new NameExpression($var, $node->getTemplateLine()));

                return new SetNode(false, new Node([$name]), new Node([$node->getNode('expr')]), $node->getTemplateLine());
            }
        }

        if (!$this->scope->has('domain')) {
            return $node;
        }

        if ($node instanceof FilterExpression && 'trans' === $node->getNode('filter')->getAttribute('value')) {