Sstalle\php7cc\NodeVisitor\YieldExpressionVisitor::enterNode PHP Метод

    public function enterNode(Node $node)
    {
        if (!($node instanceof Node\Expr\Yield_ && $node->value && $node->value instanceof Node\Expr)) {
            return;
        }
        $valueClass = get_class($node->value);
        if (isset($this->lowerPrecedenceExpressionClasses[$valueClass])) {
            $this->addContextMessage('Yielding expression with precedence lower than "yield"', $node);
        }
    }