return null;
    } else {
      Range<K> range = ranges.get(index);
      return range.contains(key) ? immutableEntry(range, values.get(index)) : null;
    }
  }

  @Override
  public Range<K> span() {
    if (ranges.isEmpty()) {
      throw new NoSuchElementException();
    }
    Range<K> firstRange = ranges.get(0);
    Range<K> lastRange = ranges.get(ranges.size() - 1);

    assertEquals(Range.closed(1, 3), ContiguousSet.closedOpen(1, 4).range());
    assertEquals(Range.closed(1, 3), ContiguousSet.create(Range.open(0, 4), integers()).range());
    assertEquals(
        Range.closed(1, 3), ContiguousSet.create(Range.openClosed(0, 3), integers()).range());

    assertEquals(
        Range.openClosed(0, 3),
        ContiguousSet.create(Range.closed(1, 3), integers()).range(OPEN, CLOSED));

      put(range, value);
      return;
    }

    Range<K> coalescedRange = coalescedRange(range, checkNotNull(value));
    put(coalescedRange, value);
  }

  /** Computes the coalesced range for the given range+value - does not mutate the map. */
  private Range<K> coalescedRange(Range<K> range, V value) {
    Range<K> coalescedRange = range;
    Entry<Cut<K>, RangeMapEntry<K, V>> lowerEntry =

        new ImmutableRangeMap.Builder<Integer, Integer>()
            .put(Range.closed(2, 4), 5)
            .put(Range.open(6, 7), 3)
            .put(Range.closedOpen(8, 10), 4)
            .put(Range.openClosed(15, 17), 2)
            .build();

    ImmutableMap<Range<Integer>, Integer> test = nonEmptyRangeMap.asMapOfRanges();

    for (Range<Integer> range : test.keySet()) {
      SerializableTester.reserializeAndAssert(range);

    assertTrue(range.encloses(Range.closed(3, 4)));

    assertFalse(range.encloses(Range.openClosed(2, 5)));
    assertFalse(range.encloses(Range.closedOpen(2, 5)));
    assertFalse(range.encloses(Range.closed(1, 4)));
    assertFalse(range.encloses(Range.closed(3, 6)));
    assertFalse(range.encloses(Range.greaterThan(3)));
    assertFalse(range.encloses(Range.lessThan(3)));
    assertFalse(range.encloses(Range.atLeast(3)));

  }

  @Override
  public void addAll(Iterable<Range<C>> ranges) {
    for (Range<C> range : ranges) {
      add(range);
    }
  }

  @Override
  public void removeAll(RangeSet<C> other) {
    removeAll(other.asRanges());
  }

  @Override
  public void removeAll(Iterable<Range<C>> ranges) {
    for (Range<C> range : ranges) {
      remove(range);
    }
  }

  @Override

        assertNull(range.getRecommendedVersion(), CHECK_VERSION_RECOMMENDATION);
        assertFalse(range.isSelectedVersionKnown(artifact), CHECK_SELECTED_VERSION_KNOWN);
        assertNull(range.getSelectedVersion(artifact), CHECK_SELECTED_VERSION);

        range = VersionRange.createFromVersionSpec("1.0");
        assertEquals("1.0", range.getRecommendedVersion().toString(), CHECK_VERSION_RECOMMENDATION);

      // The safe range is empty or the all safe code points lie in or above the
      // surrogate range. Either way the character range is empty.
      this.safeMinChar = Character.MAX_VALUE;
      this.safeMaxChar = 0;
    } else {
      // The safe range is non-empty and contains values below the surrogate
      // range but may extend above it. We may need to clip the maximum value.
      this.safeMinChar = (char) safeMin;

      return null;
    } else {
      Range<K> range = ranges.get(index);
      return range.contains(key) ? immutableEntry(range, values.get(index)) : null;
    }
  }

  @Override
  public Range<K> span() {
    if (ranges.isEmpty()) {
      throw new NoSuchElementException();
    }
    Range<K> firstRange = ranges.get(0);
    Range<K> lastRange = ranges.get(ranges.size() - 1);

      // The safe range is empty or the all safe code points lie in or above the
      // surrogate range. Either way the character range is empty.
      this.safeMinChar = Character.MAX_VALUE;
      this.safeMaxChar = 0;
    } else {
      // The safe range is non-empty and contains values below the surrogate
      // range but may extend above it. We may need to clip the maximum value.
      this.safeMinChar = (char) safeMin;