code: public static void closeWTX(final boolean abortTransaction, final INodeWriteTrx wtx, final ISession ses)
          throws TTException {
          synchronized (ses) {
              if (abortTransaction) {
                  wtx.abort();
              }
              ses.close();
          }
      }
docs: This method closes all open treetank connections concerning a
  NodeWriteTrx.
  
  @param abortTransaction
  <code>true</code> if the transaction has to be aborted, <code>false</code> otherwise.
  @param wtx
  INodeWriteTrx to be closed
  @param ses
  ISession to be closed
  @throws TreetankException