How can I identify the cache if I see its name? One belongs to malware

If Device maintenance app is launched in Samsung S8, after pressing Clean Now button, storage cleanup briefly shows different apps, storage space of which is being cleaned:

System cache OneNote TopBuzz 

I know that the last one is a malware and is not present in my list of apps, but how can I find out to which app it actually belongs? No antivirus which I tried so far reported this as a malware. But maybe there is some system analyzer which shows similar cache ownership like the above app, but with more details?

(Or maybe there is another method how to find origin of that TopBuzz symptom.)

The phone is not rooted.

Proof: $U$ is an ultrafilter of a Boolean algebra $B$ if and only if for all $x$ in $U$ exactly one of $x$,$x^*$ belongs to $U$.

I have been stuck with this problem for a while now. I have a proof that letting $ U$ be an ultrafilter, exactly one of $ x,x^*$ belongs to $ U$ for all $ x$ in $ B$ , I did this by showing that both belong to $ U$ implies that $ U=B$ which cannot be the case, and if neither long to $ U$ then a contradiction can be derived by de-Morgan’s laws. However, I’m stuck with the reverse implication, I need to prove that:

“If $ U$ is a subset of a Boolean algebra $ B$ such that $ \forall x \in B$ , exactly one of $ x \in U$ and $ x^* \in U$ is true.

Is this even the case? Any help would be greatly appreciated, thanks in advance.

How can I check if an ID belongs to a user or a group?

I’ve got a SharePoint list with a field where authorized users and/or groups are listed. I know I can use CanCurrentUserViewMembership to check if the user belongs to a specific group, but if the ID I pass belongs to a user I get an Internal Server Error.

Is there a way to check whether the ID belongs to a person or group before making this call? Taking into consideration that I’m doing this on a loop, so a lot of calls are being made.

Filter cross sell list by product it belongs to

I have extended the core cross sell functionality in order to add a custom product relation at the cart. I’m trying to output it a little differently, however, as i want to append these products to each product in the cart’s table row. This means I need to modify the cart item renderer to output the relevant products (which I’ve done), but what seems like the tricky part to me is how to only get the cross-sells for the product currently being rendered, rather than all the cross-sells.

So in my custom block, I override the core _getCollection method to get my custom relation, but it just gets all cross-sells – how would I best go about getting the products only for the current cart item?

Grateful for any pointers in the right direction (a frontender trying to do some backend work 🙂 )

protected function _getCollection() {      var_dump(Mage::registry(('current_product'))); // is null - was wishful thinking that I could use this     var_dump($  this->getData(''));      $  collection = Mage::getModel('catalog/product_link')         ->useCustomLinks()         ->getProductCollection()         ->setStoreId(Mage::app()->getStore()->getId())         ->addStoreFilter()         ->setPageSize(1);      $  this->_addProductAttributesAndPrices($  collection);      Mage::getSingleton('catalog/product_status')->addSaleableFilterToCollection($  collection);     Mage::getSingleton('catalog/product_visibility')->addVisibleInCatalogFilterToCollection($  collection);     Mage::getSingleton('cataloginventory/stock')->addInStockFilterToCollection($  collection);      return $  collection; }