src/vs/workbench/api/common/extHostTypes.ts/NotebookEdit/updateNotebookMetadata
class NotebookEdit:	static updateNotebookMetadata(newMetadata: { [key: string]: any }): NotebookEdit {
		const edit = new NotebookEdit(new NotebookRange(0, 0), []);
		edit.newNotebookMetadata = newMetadata;
		return edit;
	}