assertTrue(getMultiset().removeAll(singleton(e0())));
    assertEmpty(getMultiset());
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRetainAllIgnoresCount() {
    initThreeCopies();
    List<E> contents = copyToList(getMultiset());
    assertFalse(getMultiset().retainAll(singleton(e0())));
    expectContents(contents);
  }

  /**