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// Items in dropdowns use .dropdown-item instead of .nav-link.
if ( $depth > 0 ) {
	$atts['class'] = 'dropdown-item';
	// Test for if the menu item has 'use featured image' set to true
	$useFeaturedImage = get_field('use_featured_image', $item->ID);
	if(!empty($useFeaturedImage)) {
		$atts['style'] = 'background-image: url('.get_the_post_thumbnail_url($item->object_id).');';
	}
} else {
	$atts['class'] = 'nav-link';
}