protected final Multiset<E> getMultiset() {
    return (Multiset<E>) collection;
  }

  protected void initThreeCopies() {
    collection = getSubjectGenerator().create(e0(), e0(), e0());
  }

        getMultiset().setCount(e0(), 2, 3));
    expectUnchanged();
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSetCountConditional_oldCountTooSmallZero() {
    assertFalse(
        "setCount() with a too-small oldCount should return false",
        getMultiset().setCount(e0(), 0, 2));
    expectUnchanged();
  }

        getMultiset().setCount(e0(), 2, 3));
    expectUnchanged();
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSetCountConditional_oldCountTooSmallZero() {
    assertFalse(
        "setCount() with a too-small oldCount should return false",
        getMultiset().setCount(e0(), 0, 2));
    expectUnchanged();
  }

    int initialSize = collection.size();
    assertTrue("remove(present) should return true", collection.remove(e0()));
    assertEquals(
        "remove(present) should decrease a collection's size by one.",
        initialSize - 1,
        collection.size());
    expectMissing(e0());
  }

  @CollectionFeature.Require({SUPPORTS_REMOVE, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
  @CollectionSize.Require(SEVERAL)

  /** Returns an immutable array containing a single value. */
  public static ImmutableLongArray of(long e0) {
    return new ImmutableLongArray(new long[] {e0});
  }

  /** Returns an immutable array containing the given values, in order. */
  public static ImmutableLongArray of(long e0, long e1) {
    return new ImmutableLongArray(new long[] {e0, e1});
  }

  /** Returns an immutable array containing the given values, in order. */

  public void testIndexOf_duplicate() {
    E[] array = createSamplesArray();
    array[getNumElements() / 2] = e0();
    collection = getSubjectGenerator().create(array);
    assertEquals(
        "indexOf(duplicate) should return index of first occurrence", 0, getList().indexOf(e0()));
  }

  public void testLastIndexOf_duplicate() {
    E[] array = createSamplesArray();
    array[getNumElements() / 2] = e0();
    collection = getSubjectGenerator().create(array);
    assertEquals(
        "lastIndexOf(duplicate) should return index of last occurrence",
        getNumElements() / 2,
        getList().lastIndexOf(e0()));
  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  public void testAddAtIndex_supportedPresent() {
    getList().add(0, e0());
    expectAdded(0, e0());
  }

  @ListFeature.Require(absent = SUPPORTS_ADD_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  /*
   * absent = ZERO isn't required, since unmodList.add() must

  @CollectionFeature.Require(SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  public void testAdd_supportedPresent() {
    assertTrue("add(present) should return true", getList().add(e0()));
    expectAdded(e0());
  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  /*
   * absent = ZERO isn't required, since unmodList.add() must

          putAll(MinimalCollection.of(e3(), e0()));
          iterator.next();
        });
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutAll_unsupportedSomePresent() {
    assertThrows(
        UnsupportedOperationException.class, () -> putAll(MinimalCollection.of(e3(), e0())));
    expectUnchanged();
  }