src/vs/editor/common/viewModel/viewModelImpl.ts/HiddenAreasModel/setHiddenAreas
class HiddenAreasModel:	setHiddenAreas(source: unknown, ranges: Range[]): void {
		const existing = this.hiddenAreas.get(source);
		if (existing && rangeArraysEqual(existing, ranges)) {
			return;
		}
		this.hiddenAreas.set(source, ranges);
		this.shouldRecompute = true;
	}