code: public static Ix<Integer> range(int start, int count) {
          if (count == 0) {
              return empty();
          }
          if (count == 1) {
              return just(start);
          }
          if (count < 0) {
              throw new IllegalArgumentException("count >= 0 required but it was " + count);
          }
          return new IxRange(start, count);
      }
docs: Emits a range of incrementing integer values, starting from {@code start} and
  up to {@code count} times.
  @param start the starting value
  @param count the number of integers to emit, non-negative
  @return the new Ix instance
  @throws IllegalArgumentException if count is negative
  @since 1.0