FILE_SEPARATOR("file.separator"),

  /** Path separator (":" on UNIX). */
  PATH_SEPARATOR("path.separator"),

  /** Line separator ("\n" on UNIX). */
  LINE_SEPARATOR("line.separator"),

  /** User's account name. */
  USER_NAME("user.name"),

  /** User's home directory. */
  USER_HOME("user.home"),

  /** User's current working directory. */
  USER_DIR("user.dir");

  private final String key;

 * A mutable value of type {@code int}, for multisets to use in tracking counts of values.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class Count implements Serializable {
  private int value;

  Count(int value) {
    this.value = value;
  }

  public int get() {
    return value;
  }

  public void add(int delta) {
    value += delta;
  }

  }

  public void testAddAndGet() {
    Count holder = new Count(20);
    assertEquals(21, holder.addAndGet(1));
  }

  public void testGetAndSet() {
    Count holder = new Count(10);
    assertEquals(10, holder.getAndSet(20));
    assertEquals(20, holder.get());
  }

  public void testSet() {
    Count holder = new Count(10);
    holder.set(20);
    assertEquals(20, holder.get());
  }

  public void testAddOccurrences() {
    int originalCount = getMultiset().count(e0());
    assertEquals("old count", originalCount, getMultiset().add(e0(), 2));
    assertEquals("old count", originalCount + 2, getMultiset().count(e0()));
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testAddSeveralTimes() {
    int originalCount = getMultiset().count(e0());
    assertEquals(originalCount, getMultiset().add(e0(), 2));

  void setCountCheckReturnValue(E element, int count) {
    assertEquals(
        "multiset.setCount() should return the old count",
        getMultiset().count(element),
        setCount(element, count));
  }

  @Override
  void setCountNoCheckReturnValue(E element, int count) {
    setCount(element, count);
  }

  @CanIgnoreReturnValue
  private int setCount(E element, int count) {

  @Override
  public int setCount(E element, int count) {
    checkIsE(element);
    checkNonnegative(count, "count");
    int index = element.ordinal();
    int oldCount = counts[index];
    counts[index] = count;
    size += count - oldCount;
    if (oldCount == 0 && count > 0) {
      distinctElements++;
    } else if (oldCount > 0 && count == 0) {
      distinctElements--;
    }
    return oldCount;

    List<Entry<E>> expected = new ArrayList<>(getMultiset().entrySet());
    List<Entry<E>> actual = new ArrayList<>();
    getMultiset()
        .forEachEntry((element, count) -> actual.add(Multisets.immutableEntry(element, count)));
    Helpers.assertEqualIgnoringOrder(expected, actual);
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testForEachEntryOrdered() {

      // The JVM will return interned values for small ints.
      Integer value = random.nextInt(1000) + 128;
      int count = Math.min(random.nextInt(10) + 1, sizeRemaining);
      sizeRemaining -= count;
      hashMultiset.add(value, count);
      linkedHashMultiset.add(value, count);
      treeMultiset.add(value, count);
    }

    // TODO(kevinb): convert to assert once benchmark tests enable asserts by default

              break;
            }
          case SET_COUNT:
            {
              int newValue = random.nextInt(3);
              int oldValue = multiset.setCount(key, newValue);
              deltas[keyIndex] += (newValue - oldValue);
              break;
            }
          case SET_COUNT_IF:
            {
              int newValue = random.nextInt(3);

    ms.add(Color.RED);
    assertEquals(0, ms.count(Color.BLUE));
    assertEquals(1, ms.count(Color.YELLOW));
    assertEquals(2, ms.count(Color.RED));
  }

  public void testCollectionCreate() {
    Multiset<Color> ms = EnumMultiset.create(asList(Color.RED, Color.YELLOW, Color.RED));
    assertEquals(0, ms.count(Color.BLUE));
    assertEquals(1, ms.count(Color.YELLOW));
    assertEquals(2, ms.count(Color.RED));
  }