public static function getIconSizesForSubtype($hook, $type, $sizes, $params)
{
$subtype = elgg_extract('entity_subtype', $params);
$icon_type = elgg_extract('type', $params);
if ($type == 'object' && $subtype == 'foo' && $icon_type == 'icon') {
return self::getTestSizes();
}
}