src/vs/workbench/contrib/notebook/common/services/notebookSimpleWorker.ts/NotebookEditorSimpleWorker/acceptRemovedModel
class NotebookEditorSimpleWorker:	public acceptRemovedModel(strURL: string): void {
		if (!this._models[strURL]) {
			return;
		}
		delete this._models[strURL];
	}