src/vs/workbench/contrib/notebook/browser/viewModel/codeCellViewModel.ts/CodeCellViewModel/getOutputOffsetInContainer
class CodeCellViewModel:	getOutputOffsetInContainer(index: number) {
		this._ensureOutputsTop();

		if (index >= this._outputCollection.length) {
			throw new Error('Output index out of range!');
		}

		return this._outputsTop!.getPrefixSum(index - 1);
	}