src/vs/editor/browser/services/editorWorkerService.ts/EditorWorkerClient/_getOrCreateModelManager
class EditorWorkerClient:	private _getOrCreateModelManager(proxy: EditorSimpleWorker): EditorModelManager {
		if (!this._modelManager) {
			this._modelManager = this._register(new EditorModelManager(proxy, this._modelService, this._keepIdleModels));
		}
		return this._modelManager;
	}