@Override
  public void fromData(DataInput in,
      DeserializationContext context) throws IOException, ClassNotFoundException {
    super.fromData(in, context);
    cancelled = in.readBoolean();
    snapshot = DataSerializer.readObject(in);
  }
Populates the collection of sub-region snapshots for the parentSnapShot with snapshots for the
regions given.

@param parentSnapShot RegionSubRegionSnapshot of a parent region
@param regions collection of sub-regions of the region represented by parentSnapShot
@param cache cache instance is used for to get the LogWriter instance to log exceptions if any
geode-core/src/main/java/org/apache/geode/internal/admin/remote/RegionSubRegionsSizeResponse.java