src/vs/workbench/contrib/notebook/browser/viewModel/notebookViewModel.ts/NotebookViewModel/nearestCodeCellIndex
class NotebookViewModel:	nearestCodeCellIndex(index: number /* exclusive */) {
		const nearest = this.viewCells.slice(0, index).reverse().findIndex(cell => cell.cellKind === CellKind.Code);
		if (nearest > -1) {
			return index - nearest - 1;
		} else {
			const nearestCellTheOtherDirection = this.viewCells.slice(index + 1).findIndex(cell => cell.cellKind === CellKind.Code);
			if (nearestCellTheOtherDirection > -1) {
				return index + 1 + nearestCellTheOtherDirection;
			}
			return -1;
		}
	}