gradient_server-1.0.x-dev/modules/source/source.routing.yml

source.add_feed:
  path: '/feed/add/{feed_type}/{source}'
  defaults:
    _controller: 'Drupal\source\Controller\AddFeed::bySource'
    _title_callback: 'Drupal\source\Controller\AddFeed::bySourceTitle'
  requirements:
    _entity_create_access: 'feeds_feed:{feed_type}'
    _entity_access: 'source.update'
  options:
    parameters:
      feed_type:
        type: entity:feeds_feed_type
      source:
        type: entity:source