public void addGatewaySenderId(String gatewaySenderId) {
      synchronized (this) {
        if (gatewaySenderIds == null) {
          gatewaySenderIds = new CopyOnWriteArraySet<>();
          gatewaySenderIds.add(gatewaySenderId);
        } else {
          if (gatewaySenderIds.contains(gatewaySenderId)) {
            throw new IllegalArgumentException(
                String.format("gateway-sender-id %s is already added",
                    gatewaySenderId));
          }
          gatewaySenderIds.add(gatewaySenderId);
        }
        setHasGatewaySenderIds(true);
      }
    }
Constructs an instance of {@code RegionAttributes} with default settings.

@see AttributesFactory
geode-core/src/main/java/org/apache/geode/cache/AttributesFactory.java