public int getNumDataStores() {
    final int numProfs = getNumProfiles();
    if (lastActiveProfiles != numProfs) {
      numDataStores = adviseDataStore().size();
      lastActiveProfiles = numProfs;
    }
    return numDataStores;
  }
for internal use, required for DataSerializer.readObject
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/RegionAdvisor.java