src/vs/editor/contrib/folding/browser/foldingModel.ts/FoldingModel/update
class FoldingModel:	public update(newRegions: FoldingRegions, blockedLineNumers: number[] = []): void {
		const foldedOrManualRanges = this._currentFoldedOrManualRanges(blockedLineNumers);
		const newRanges = FoldingRegions.sanitizeAndMerge(newRegions, foldedOrManualRanges, this._textModel.getLineCount());
		this.updatePost(FoldingRegions.fromFoldRanges(newRanges));
	}