src/vs/editor/contrib/folding/indentRangeProvider.ts/IndentRangeProvider/compute
class IndentRangeProvider:	compute(cancelationToken: CancellationToken): Promise<FoldingRegions> {
		let foldingRules = LanguageConfigurationRegistry.getFoldingRules(this.editorModel.getLanguageIdentifier().id);
		let offSide = foldingRules && !!foldingRules.offSide;
		let markers = foldingRules && foldingRules.markers;
		return Promise.resolve(computeRanges(this.editorModel, offSide, markers));
	}