HashMultiset.create(Arrays.<@Nullable String>asList("a", null, "b"));
    assertThrows(NullPointerException.class, () -> ImmutableMultiset.copyOf((Multiset<String>) c));
  }

  public void testCopyOf_iterator_empty() {
    Iterator<String> iterator = emptyIterator();
    Multiset<String> multiset = ImmutableMultiset.copyOf(iterator);
    assertTrue(multiset.isEmpty());
  }

    Collection<TestEnum> c = EnumSet.of(TestEnum.A, TestEnum.B, TestEnum.D);
    Set<TestEnum> set = copyOf(c);
    assertEquals(3, set.size());
    assertEquals(c, set);
  }

  public void testCopyOf_iterator_empty() {
    Iterator<String> iterator = emptyIterator();
    Set<String> set = copyOf(iterator);
    assertEquals(Collections.<String>emptySet(), set);
    assertSame(this.<String>of(), set);
  }

        HashMultiset.create(Arrays.<@Nullable String>asList("a", null, "b"));
    assertThrows(NullPointerException.class, () -> ImmutableMultiset.copyOf((Multiset<String>) c));
  }

  public void testCopyOf_iterator_empty() {
    Iterator<String> iterator = emptyIterator();
    Multiset<String> multiset = ImmutableMultiset.copyOf(iterator);
    assertTrue(multiset.isEmpty());
  }

    Collection<@Nullable String> c = MinimalCollection.of("a", null, "b");
    assertThrows(NullPointerException.class, () -> ImmutableList.copyOf((Collection<String>) c));
  }

  public void testCopyOf_iterator_empty() {
    Iterator<String> iterator = emptyIterator();
    List<String> list = ImmutableList.copyOf(iterator);
    assertEquals(emptyList(), list);
  }

  public void testCopyOf_iterator_oneElement() {

    Collection<@Nullable String> c = MinimalCollection.of("a", null, "b");
    assertThrows(NullPointerException.class, () -> ImmutableList.copyOf((Collection<String>) c));
  }

  public void testCopyOf_iterator_empty() {
    Iterator<String> iterator = emptyIterator();
    List<String> list = ImmutableList.copyOf(iterator);
    assertEquals(emptyList(), list);
  }

  public void testCopyOf_iterator_oneElement() {