code: public double totalCount() {
      if (depth() == 1) {
        return total; // I think this one is always OK.  Not very principled here, though.
      } else {
        double result = 0.0;
        for (K o: topLevelKeySet()) {
          result += conditionalizeOnce(o).totalCount();
        }
        return result;
      }
    }
docs: returns the total count of objects in the GeneralizedCounter.