#19554¹ introduced the use of `Map`, which needs to be enabled (still) to be used in older browsers that do not support it yet, like the browser used for integration tests.

See https://babeljs.io/learn-es2015/#ecmascript-2015-features-map-set-weak-map-weak-set

[1]https://github.com/theforeman/foreman/pull/4792