}

    {
      ImmutableMultiset.Builder<String> builder = ImmutableMultiset.builder();
    Multiset<@Nullable String> multisetWithNull =
        LinkedHashMultiset.create(Arrays.<@Nullable String>asList("a", null, "b"));
      assertThrows(
          NullPointerException.class, () -> builder.addAll((Multiset<String>) multisetWithNull));
    }
  }

        return HashMultiset.create(contents);
      }
    },
    LinkedHashMultisetImpl {
      @Override
      public <E extends Comparable<E>> Multiset<E> create(Collection<E> contents) {
        return LinkedHashMultiset.create(contents);
      }
    },
    ConcurrentHashMultisetImpl {
      @Override
      public <E extends Comparable<E>> Multiset<E> create(Collection<E> contents) {

    }

    {
      ImmutableSortedMultiset.Builder<String> builder = ImmutableSortedMultiset.naturalOrder();
      Multiset<String> multisetWithNull = LinkedHashMultiset.create(asList("a", null, "b"));
      assertThrows(NullPointerException.class, () -> builder.addAll(multisetWithNull));
    }
  }

  public void testBuilderAddCopiesHandlesNullsCorrectly() {

    }

    {
      ImmutableMultiset.Builder<String> builder = ImmutableMultiset.builder();
    Multiset<@Nullable String> multisetWithNull =
        LinkedHashMultiset.create(Arrays.<@Nullable String>asList("a", null, "b"));
      assertThrows(
          NullPointerException.class, () -> builder.addAll((Multiset<String>) multisetWithNull));
    }
  }

 *
 * <h3>Implementations</h3>
 *
 * <ul>
 *   <li>{@link ImmutableMultiset}
 *   <li>{@link ImmutableSortedMultiset}
 *   <li>{@link HashMultiset}
 *   <li>{@link LinkedHashMultiset}
 *   <li>{@link TreeMultiset}
 *   <li>{@link EnumMultiset}
 *   <li>{@link ConcurrentHashMultiset}
 * </ul>
 *
 * <p>If your values may be zero, negative, or outside the range of an int, you may wish to use

 *
 * <h3>Implementations</h3>
 *
 * <ul>
 *   <li>{@link ImmutableMultiset}
 *   <li>{@link ImmutableSortedMultiset}
 *   <li>{@link HashMultiset}
 *   <li>{@link LinkedHashMultiset}
 *   <li>{@link TreeMultiset}
 *   <li>{@link EnumMultiset}
 *   <li>{@link ConcurrentHashMultiset}
 * </ul>
 *
 * <p>If your values may be zero, negative, or outside the range of an int, you may wish to use