src/vs/workbench/contrib/folding/browser/folding.contribution.ts/DefaultFoldingRangeProvider/_selectFoldingRangeProvider
class DefaultFoldingRangeProvider:	private _selectFoldingRangeProvider(providers: FoldingRangeProvider[], document: ITextModel): FoldingRangeProvider[] {
		const value = this._configurationService.getValue<string>(DefaultFoldingRangeProvider.configName, { overrideIdentifier: document.getLanguageId() });
		if (value) {
			return providers.filter(p => p.id === value);
		}
		return providers;
	}