ITransaction reg = ThreadContext.getTransaction();
    if (reg == null) {
      throw new ProcessingException("no ITransaction available, use ServerJob to run transaction");
    }
    P_Neo4jTransactionMember member = (P_Neo4jTransactionMember) reg.getMember(getTransactionMemberId());
    if (member == null) {
      _Neo4jConnection_ conn;
      try {
        conn = _create or lease or get the connection_
        member = new P_Neo4jTransactionMember(getTransactionMemberId(), conn);
        reg.registerMember(member);
        // this is the start of the transaction
        execBeginTransaction();
      }
      catch (ProcessingException e) {
        throw e;
      }
      catch (Throwable e) {
        throw new ProcessingException("getTransaction", e);
      }
    }
    return member.getConnection();

    String tid = getConfiguredTransactionMemberId();
    if (tid == null) {
      tid = getClass().getSimpleName() + "." + "transaction";
    }
    setTransactionMemberId(tid);

  private final class P_Neo4jTransactionMember extends AbstractTransactionMember {
    private final _Neo4jConnection_ m_conn;
    /** true during completion phase (commit/rollback) */
    private boolean m_finishingTransaction;

    public P_Neo4jTransactionMember(String transactionMemberId, _Neo4jConnection_ conn) {
      super(transactionMemberId);
      m_conn = conn;
    }

    public _Neo4jConnection_ getConnection() {
      return m_conn;
    }

    protected void setFinishingTransaction(boolean finishingTransaction) {
      m_finishingTransaction = finishingTransaction;
    }

    @Override
    public boolean needsCommit() {
      return true;
    }

    @Override
    public boolean commitPhase1() {
      return execPreCommit(m_conn);
    }

    @Override
    public void commitPhase2() {
      try {
        // this is the end of the transaction
        try {
          setFinishingTransaction(true);
          execEndTransaction(false);
        }
        finally {
          setFinishingTransaction(false);
        }
        execCommit(m_conn);
      }
      catch (Exception e) {
        LOG.error(null, e);
      }
    }

    @Override
    public void rollback() {
      try {
        // this is the end of the transaction
        try {
          setFinishingTransaction(true);
          execEndTransaction(false);
        }
        finally {
          setFinishingTransaction(false);
        }
        execRollback(m_conn);
      }
      catch (Exception e) {
        if (!ThreadContext.getTransaction().isCancelled()) {
          LOG.error(null, e);
        }
      }
    }

    @Override
    public void release() {
      releaseConnection(m_conn);
    }
  }// end private class

  Transaction tx = db.beginTx(); // starts a transaction

  tx.success(); // marks a transaction as successful
  tx.failure(); // marks a transaction as failed

  tx.close(); // ends the transaction