shadows/framework/src/main/java/org/robolectric/shadows/ShadowSubscriptionManager.java
public void setNetworkRoamingStatus(int simSubscriptionId, boolean isNetworkRoaming) {
    if (isNetworkRoaming) {
      roamingSimSubscriptionIds.add(simSubscriptionId);
    } else {
      roamingSimSubscriptionIds.remove(simSubscriptionId);
    }
  }
public void setNetworkRoamingStatus(int simSubscriptionId, boolean isNetworkRoaming) {
    if (isNetworkRoaming) {
      roamingSimSubscriptionIds.add(simSubscriptionId);
    } else {
      roamingSimSubscriptionIds.remove(simSubscriptionId);
    }
  }
If isNetworkRoaming is set, it will mark the provided sim subscriptionId as roaming in a local
cache. If isNetworkRoaming is unset it will remove the subscriptionId from the local cache. The
local cache is used to provide roaming status returned by {@link #isNetworkRoaming}.