code: @Implementation(minSdk = LOLLIPOP_MR1)
    protected SubscriptionInfo getActiveSubscriptionInfo(int subId) {
      if (subscriptionList == null) {
        return null;
      }
      for (SubscriptionInfo info : subscriptionList) {
        if (info.getSubscriptionId() == subId) {
          return info;
        }
      }
      return null;
    }
docs: Returns subscription that were set via {@link #setActiveSubscriptionInfoList} if it can find
  one with the specified id or null if none found.