src/vs/workbench/contrib/notebook/browser/controller/cellOperations.ts/computeCellLinesContents
export function computeCellLinesContents(cell: ICellViewModel, splitPoints: IPosition[]): string[] | null {
	const rangeBoundaries = _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;
}