src/vs/editor/contrib/folding/folding.ts/FoldRecursivelyAction/invoke
class FoldRecursivelyAction:	invoke(_foldingController: FoldingController, foldingModel: FoldingModel, editor: ICodeEditor): void {
		let selectedLines = this.getSelectedLines(editor);
		setCollapseStateLevelsDown(foldingModel, true, Number.MAX_VALUE, selectedLines);
	}