src/vs/workbench/contrib/notebook/browser/contrib/cellCommands/cellCommands.ts/forEachCell
function forEachCell(editor: INotebookEditor, callback: (cell: ICellViewModel, index: number) => void) {
	for (let i = 0; i < editor.getLength(); i++) {
		const cell = editor.cellAt(i);
		callback(cell!, i);
	}
}