@Override
  public void toData(DataOutput out) throws IOException {
    // The proxy isn't being serialized right now, but if it needs to be
    // then the proxyId would probably be the best way to do it.
    DataSerializer.writeString(regionName, out);
    DataSerializer.writeHashSet((HashSet<?>) keysOfInterest, out);
    DataSerializer.writePrimitiveInt(interestType, out);
    DataSerializer.writePrimitiveBoolean(isRegister, out);
  }
Constructor.

@param regionName The name of the region to which this interest event belongs
geode-core/src/main/java/org/apache/geode/internal/cache/InterestRegistrationEventImpl.java