private void assertZeroToZero() {
    assertSetCount(e3(), 0);
  }

  private void assertOneToOne() {
    assertSetCount(e0(), 1);
  }

  private void assertThreeToThree() {
    initThreeCopies();
    assertSetCount(e0(), 3);
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSetCount_zeroToZero_addSupported() {
    assertZeroToZero();
  }

    assertNull(navigableSet.pollFirst());
  }

  @CollectionSize.Require(ZERO)
  public void testEmptySetNearby() {
    assertNull(navigableSet.lower(e0()));
    assertNull(navigableSet.floor(e0()));
    assertNull(navigableSet.ceiling(e0()));
    assertNull(navigableSet.higher(e0()));
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testEmptySetPollLast() {

  public void testAddAll_withDuplicates() {
    MinimalCollection<E> elementsToAdd = MinimalCollection.of(e0(), e1(), e0(), e1());
    assertTrue("addAll(hasDuplicates) should return true", getList().addAll(elementsToAdd));
    expectAdded(e0(), e1(), e0(), e1());
  }

    new IteratorTester<E>(
        4,
        MODIFIABLE,
        getSubjectGenerator().order(asList(e0(), e1(), e1(), e2())),
        IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override
      protected Iterator<E> newTargetIterator() {
        return getSubjectGenerator().create(e0(), e1(), e1(), e2()).iterator();
      }
    }.test();
  }

    assertEquals("size1Queue.poll() should return first element", e0(), getQueue().poll());
    expectMissing(e0());
  }

  @CollectionFeature.Require({KNOWN_ORDER, SUPPORTS_REMOVE})
  @CollectionSize.Require(SEVERAL)
  public void testPoll_sizeMany() {
    assertEquals("sizeManyQueue.poll() should return first element", e0(), getQueue().poll());
    expectMissing(e0());
  }

  @CollectionSize.Require(SEVERAL)
  public void testRetainAll_countIgnored() {
    resetContainer(getSubjectGenerator().create(e0(), e2(), e1(), e0()));
    assertTrue(getList().retainAll(asList(e0(), e1())));
    assertContentsInOrder(getList(), e0(), e1(), e0());
  }

    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)

    assertEquals("size1Queue.remove() should return first element", e0(), getQueue().remove());
    expectMissing(e0());
  }

  @CollectionFeature.Require({KNOWN_ORDER, SUPPORTS_REMOVE})
  @CollectionSize.Require(SEVERAL)
  public void testRemove_sizeMany() {
    assertEquals("sizeManyQueue.remove() should return first element", e0(), getQueue().remove());
    expectMissing(e0());
  }

  private void assertZeroToZero() {
    assertSetCount(e3(), 0);
  }

  private void assertOneToOne() {
    assertSetCount(e0(), 1);
  }

  private void assertThreeToThree() {
    initThreeCopies();
    assertSetCount(e0(), 3);
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSetCount_zeroToZero_addSupported() {
    assertZeroToZero();
  }

        "multiset.elementSet().contains(present) returned false",
        getMultiset().elementSet().contains(e0()));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testEntrySet_contains() {
    assertTrue(
        "multiset.entrySet() didn't contain [present, 1]",
        getMultiset().entrySet().contains(Multisets.immutableEntry(e0(), 1)));
  }

  public void testEntrySet_contains_count0() {
    assertFalse(