open-vault/ui/app/routes/vault/cluster/settings/mount-secret-backend.js

import Route from '@ember/routing/route';
import UnloadModelRoute from 'vault/mixins/unload-model-route';
import UnsavedModelRoute from 'vault/mixins/unsaved-model-route';

export default Route.extend(UnloadModelRoute, UnsavedModelRoute, {
  // intentionally blank - we don't want a model until one is
  // created via the form in the controller
  model() {
    return {};
  },
  activate() {
    this.store.unloadAll('secret-engine');
  },
});