src/vs/editor/contrib/folding/browser/folding.ts/FoldingController/onHiddenRangesChanges
class FoldingController:	private onHiddenRangesChanges(hiddenRanges: IRange[]) {
		if (this.hiddenRangeModel && hiddenRanges.length && !this._restoringViewState) {
			let selections = this.editor.getSelections();
			if (selections) {
				if (this.hiddenRangeModel.adjustSelections(selections)) {
					this.editor.setSelections(selections);
				}
			}
		}
		this.editor.setHiddenAreas(hiddenRanges);
	}