android/guava/src/com/google/common/collect/ContiguousSet.java
@Beta
  public static ContiguousSet<Integer> closed(int lower, int upper) {
    return create(Range.closed(lower, upper), DiscreteDomain.integers());
  }
@Beta
  public static ContiguousSet<Integer> closed(int lower, int upper) {
    return create(Range.closed(lower, upper), DiscreteDomain.integers());
  }
Returns a nonempty contiguous set containing all {@code int} values from {@code lower}
(inclusive) to {@code upper} (inclusive). (These are the same values contained in {@code
Range.closed(lower, upper)}.)

@throws IllegalArgumentException if {@code lower} is greater than {@code upper}
@since 23.0