docs: public static IntList range(int start, int to, int step)
      {
          if(to < start)
              throw new RuntimeException("starting index " + start + " must be less than or equal to ending index" + to);
          else if(step < 1)
              throw new RuntimeException("Step size must be a positive integer, not " + step);
          IntList toRet = new IntList((to-start)/step);
          for(int i = start; i < to; i+=step)
              toRet.add(i);
          return toRet;
      }