src/vs/editor/browser/controller/mouseTarget.ts/MouseTargetFactory/_hitTestScrollbarSlider
class MouseTargetFactory:	private static _hitTestScrollbarSlider(ctx: HitTestContext, request: ResolvedHitTestRequest): IMouseTarget | null {
		if (ElementPath.isChildOfScrollableElement(request.targetPath)) {
			if (request.target && request.target.nodeType === 1) {
				const className = request.target.className;
				if (className && /\b(slider|scrollbar)\b/.test(className)) {
					const possibleLineNumber = ctx.getLineNumberAtVerticalOffset(request.mouseVerticalOffset);
					const maxColumn = ctx.viewModel.getLineMaxColumn(possibleLineNumber);
					return request.fulfillScrollbar(new Position(possibleLineNumber, maxColumn));
				}
			}
		}
		return null;
	}