pcb-8.x-2.2/modules/pcb_memcache/pcb_memcache.services.yml

services:
  cache.backend.permanent_memcache:
    class: Drupal\pcb_memcache\Cache\PermanentMemcacheBackendFactory
    arguments:
      - '@memcache.factory'
      - '@cache_tags.invalidator.checksum'
      - '@memcache.timestamp.invalidator.bin'