code: @Override
      public LogCursor recoverableUnits() throws LogClosedException
      {
          if (tc.isEntryEnabled())
              Tr.entry(tc, "recoverableUnits", this);
  
          final LogCursor cursor = recoverableUnits(_failureScope);
  
          if (tc.isEntryEnabled())
              Tr.exit(tc, "recoverableUnits", cursor);
  
          return cursor;
      }
docs: Added to support RecoveryLog interface so that RecoveryLogImpl can store all types of RecoveryLog (eg new SQL log)