code: func (l *kvLedger) NewQueryExecutor() (ledger.QueryExecutor, error) {
  	return l.txtmgmt.NewQueryExecutor(util.GenerateUUID())
  }
docs: // NewQueryExecutor gives handle to a query executor.
  // A client can obtain more than one 'QueryExecutor's for parallel execution.
  // Any synchronization should be performed at the implementation level if required