code: public static IntList range(int start, int end, int step)
      {
          IntList l = new IntList((end-start)/step +1);
          for(int i = start; i < end; i++)
              l.add(i);
          return l;
      }
docs: Returns a new IntList containing values in the given range
  @param start the starting value (inclusive)
  @param end the ending value (exclusive)
  @param step the step size
  @return a new IntList populated by integer values as if having run through a  for loop