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