src/vs/workbench/contrib/notebook/browser/viewModel/notebookViewModel.ts/NotebookViewModel/computeCellLinesContents
class NotebookViewModel:	computeCellLinesContents(cell: ICellViewModel, splitPoints: IPosition[]): string[] | null {
		const rangeBoundaries = this._splitPointsToBoundaries(splitPoints, cell.textBuffer);
		if (!rangeBoundaries) {
			return null;
		}
		const newLineModels: string[] = [];
		for (let i = 1; i < rangeBoundaries.length; i++) {
			const start = rangeBoundaries[i - 1];
			const end = rangeBoundaries[i];

			newLineModels.push(cell.textBuffer.getValueInRange(new Range(start.lineNumber, start.column, end.lineNumber, end.column), EndOfLinePreference.TextDefined));
		}

		return newLineModels;
	}