Neos\Neos\Service\ContentElementWrappingService::addCssClasses PHP Method

    protected function addCssClasses(array $attributes, NodeInterface $node, array $initialClasses = [])
    {
        $classNames = $initialClasses;
        // FIXME: The `dimensionsAreMatchingTargetDimensionValues` method should become part of the NodeInterface if it is used here .
        if ($node instanceof Node && !$node->dimensionsAreMatchingTargetDimensionValues()) {
            $classNames[] = 'neos-contentelement-shine-through';
        }
        if ($classNames !== []) {
            $attributes['class'] = implode(' ', $classNames);
        }
        return $attributes;
    }