Trying to declutter my Macbook Pro Retina's SSD. Found that 22.78GB are being taken up in the 'Private' hidden folder. In private>var>vm the total size of that folder is 21.47GB. The sleepimage file makes up 17.18GBs of this and 'swapfile's ranging from 0-7 make up the remainder. My macbook has 16GB of RAM. Is it normal for this much space to be used up or can I clear it?