public void listChanged(ListEvent listChanges) {
// write the change to disc
try {
ListEvent listChangesCopy = listChanges.copy();
Bufferlo listChangesBytes = ListEventToBytes.toBytes(listChangesCopy, byteCoder);
storage.put(new Integer(nextUpdateId), new Chunk(listChangesBytes));
nextUpdateId++;
} catch(IOException e) {
throw new IllegalStateException(e.getMessage());
}