assertEquals(ImmutableSortedMap.of(2, 0, 4, 0, 6, 0), Maps.subMap(map, Range.atMost(7)));
    assertEquals(map, Maps.subMap(map, Range.atMost(20)));
  }

  @GwtIncompatible // NavigableMap
  public void testSubMap_unboundedRange() {
    ImmutableSortedMap<Integer, Integer> map = ImmutableSortedMap.of(2, 0, 4, 0, 6, 0, 8, 0, 10, 0);

    assertEquals(map, Maps.subMap(map, Range.<Integer>all()));
  }