docs: public FilterCellFastStr addNewCell(int hashcode, int length) {
          // check for wildcard
          if ((hashcode != 0) || (length != 0)) {
              // not a wildcard
              if (nextCell == null) {
                  // no next node on this tree, so add one
                  nextCell = new FastSynchHashTable();
              }
  
              FilterCellFastStr newCell = new FilterCellFastStr();
              newCell.hashLength = length;
              nextCell.put(hashcode, newCell);
  
              return newCell;
          }
          // entry is a wildcard, create wildcode node if it doesn't exist
          if (wildcardCell == null) {
              wildcardCell = new FilterCellFastStr();
          }
          return wildcardCell;
      }