docs: public int maximumFringeImbalance()
      {
          int maxBal;
          GBSNode q = root();
          if (q.leftChild() == null)
          {
              maxBal = kFactor() - 1;
              if (maxBal < 3)
                  maxBal = 3;
          }
          else
          {
              if ((kFactor() % 3) == 0)
                  maxBal = kFactor() + 2;
              else
                  maxBal = kFactor() + 1;
          }
          return maxBal;
      }