postoffice-1.0.x-dev/extensions/postoffice_file/postoffice_file.services.yml

services:
  twig.extension.postoffice_file:
    class: Drupal\postoffice_file\Template\TwigExtension
    arguments: ['@renderer' ]
    tags:
      - { name: twig.extension }
  postoffice_file.attachment_subscriber:
    class: \Drupal\postoffice_file\EventSubscriber\FileAttachmentSubscriber
    tags:
      - { name: event_subscriber }
  postoffice_file.adjustment_subscriber:
    class: \Drupal\postoffice_file\EventSubscriber\FileAdjustmentSubscriber
    arguments: ['@request_stack']
    tags:
      - { name: event_subscriber }