docs: public Object[][] getStatsRows(boolean interval, final Long now) {
          this.now = now;
          /*
           * Synchronizing on this allows derived classes to maintain thread safety
           */
          synchronized (this) {
              Iterator<Object> i = getStatsRowKeyIterator(interval);
              ArrayList<Object[]> rows = new ArrayList<Object[]>();
              while (i.hasNext()) {
                  Object rowKey = i.next();
                  Object rowValues[] = new Object[columns.size()];
                  updateStatsRow(rowKey, rowValues);
                  rows.add(rowValues);
              }
              return rows.toArray(new Object[0][]);
          }
      }