src/vs/workbench/contrib/notebook/browser/notebookEditorWidget.ts/NotebookEditorWidget/_nearestCodeCellIndex
class NotebookEditorWidget:	private _nearestCodeCellIndex(index: number /* exclusive */) {
		if (!this.viewModel) {
			return -1;
		}

		return this.viewModel.nearestCodeCellIndex(index);
	}