}
        }
      }
    }
  }

  public void testSpanEmpty() {
    assertThrows(NoSuchElementException.class, () -> ImmutableRangeMap.of().span());
  }

  public void testSpanSingleRange() {
    for (Range<Integer> range : RANGES) {
      RangeMap<Integer, Integer> rangemap =
          ImmutableRangeMap.<Integer, Integer>builder().put(range, 1).build();
      assertEquals(range, rangemap.span());