@Override
    public void toData(DataOutput dout,
        SerializationContext context) throws IOException {
      super.toData(dout, context);
      DataSerializer.writeObject(relayRecipient, dout);
      dout.writeInt(processorId);
      dout.writeInt(processorType);
      dout.writeBoolean(allRegions);
      if (!allRegions) {
        DataSerializer.writeString(regionPath, dout);
      }
    }
returns a set of all DistributedRegions for allRegions processing
geode-core/src/main/java/org/apache/geode/internal/cache/StateFlushOperation.java