docs: public void rollback()
      {
          try
          {
              Iterator iter = mvOrderOfIds.iterator();
              while(iter.hasNext())
              {
                  ObjectEnvelope mod = (ObjectEnvelope) mhtObjectEnvelopes.get(iter.next());
                  if(log.isDebugEnabled())
                      log.debug("rollback: " + mod);
                  // if the Object has been modified by transaction, mark object as dirty
                  if(mod.hasChanged(transaction.getBroker()))
                  {
                      mod.setModificationState(mod.getModificationState().markDirty());
                  }
                  mod.getModificationState().rollback(mod);
              }
          }
          finally
          {
              needsCommit = false;
          }
          afterWriteCleanup();
      }