docs: public static VoltTable aggregateStats(VoltTable stats) throws IllegalArgumentException
      {
          stats.resetRowPosition();
          if (stats.getRowCount() == 0) {
              return stats;
          }
  
          String role = null;
          Map<Byte, State> states = new TreeMap<>();
          while (stats.advanceRow()) {
              final byte clusterId = (byte) stats.getLong(CN_REMOTE_CLUSTER_ID);
              final String curRole = stats.getString(CN_ROLE);
              if (role == null) {
                  role = curRole;
              } else if (!role.equals(curRole)) {
                  throw new IllegalArgumentException("Inconsistent DR role across cluster nodes: " + stats.toFormattedString(false));
              }
  
              final State state = State.valueOf(stats.getString(CN_STATE));
              states.put(clusterId, state.and(states.get(clusterId)));
          }
  
          // Remove the -1 placeholder if there are real cluster states
          if (states.size() > 1) {
              states.remove((byte) -1);
          }
  
          assert role != null;
          stats.clearRowData();
          for (Map.Entry<Byte, State> e : states.entrySet()) {
              stats.addRow(role, e.getValue().name(), e.getKey());
          }
          return stats;
      }