drupalcampbristol/core/modules/page_cache/page_cache.services.yml

services:
  http_middleware.page_cache:
    class: Drupal\page_cache\StackMiddleware\PageCache
    arguments: ['@cache.render', '@page_cache_request_policy', '@page_cache_response_policy']
    tags:
      - { name: http_middleware, priority: 200, responder: true }