I'm trying to find the best way to modify products collection for products grid in admin. In particular, to add additional filter to the collection. I don't want to override the grid's block to achieve that. Looks like I'm stuck and cant find a point to start using DI in this case. Also, I can't find any event for loading grid collection as it was in Magento 1.x If someone has experience in this I would be very appreciate for any info.