library_manager-8.x-1.0/tests/library_manager_test/library_manager_test.libraries.yml

library_manager_test:
  version: 2.3.4
  js:
    js/example.js: {}
    /libraries/example/global.js: {}
    http://example.com/external.js: {external: true}
  css:
    theme:
      css/example.css: {}
      /libraries/example/global.css: {}
      http://example.com/external.css: {external: true}
  dependencies:
    - core/jquery
    - core/drupal
    - core/drupal.dialog.ajax