private enum SupplierFunctionImpl implements SupplierFunction<@Nullable Object> {
    INSTANCE;

    // Note: This makes T a "pass-through type"
    @Override
    @CheckForNull
    public Object apply(Supplier<@Nullable Object> input) {
      return input.get();
    }

    @Override
    public String toString() {

     *
     * <p>This method is used when testing iterators without a known ordering. We poll the target
     * iterator's next element and pass it to the reference iterator through this method so it can
     * return the same element. This enables the assertion to pass and the reference iterator to
     * properly update its state.
     */
    void promoteToNext(E e) {

    checkFromStringCase("[]:80", 1, null, 99, false);
    checkFromStringCase("[]bad", 1, null, 99, false);
  }

  public void testFromStringParseableNonsense() {
    // Examples of nonsense that gets through.
    checkFromStringCase("[[:]]", 86, "[:]", 86, false);
    checkFromStringCase("x:y:z", 87, "x:y:z", 87, false);
    checkFromStringCase("", 88, "", 88, false);
    checkFromStringCase(":", 99, "", 99, false);

  interface ConcurrentlyMutatedList<E> extends List<E> {
    /**
     * The elements of a {@link ConcurrentlyMutatedList} are added and removed over time. This
     * method returns every state that the list has passed through at some point.
     */
    Set<List<E>> getAllStates();
  }

  /**
   * Returns a {@link ConcurrentlyMutatedList} that performs the given operations as its concurrent

    this.nodeIterator = graph.nodes().iterator();
  }

  /**
   * Called after {@link #successorIterator} is exhausted. Advances {@link #node} to the next node
   * and updates {@link #successorIterator} to iterate through the successors of {@link #node}.
   */
  final boolean advance() {
    checkState(!successorIterator.hasNext());
    if (!nodeIterator.hasNext()) {
      return false;
    }
    node = nodeIterator.next();

    return CollectCollectors.toMultiset(elementFunction, countFunction, multisetSupplier);
  }

  /**
   * Returns an unmodifiable view of the specified multiset. Query operations on the returned
   * multiset "read through" to the specified multiset, and attempts to modify the returned multiset
   * result in an {@link UnsupportedOperationException}.
   *
   * <p>The returned multiset will be serializable if the specified multiset is serializable.

        new AbstractIterator<Integer>() {
          @Override
          public Integer computeNext() {
            throw exception;
          }
        };

    // It should pass through untouched
    try {
      iter.hasNext();
      fail("No exception thrown");
    } catch (SomeUncheckedException e) {
      assertSame(exception, e);
    }
  }

        new AbstractIterator<Integer>() {
          @Override
          public Integer computeNext() {
            throw exception;
          }
        };

    // It should pass through untouched
    try {
      iter.hasNext();
      fail("No exception thrown");
    } catch (SomeUncheckedException e) {
      assertSame(exception, e);
    }
  }

   * there's no problem. The reason: {@link EqualsTester} tests {@code null} and identical inputs
   * directly against {@code equals()} rather than through the {@code Equivalence}.
   */
  private final Equivalence<? super T> equivalence;

  private final String relationshipName;
  private final String hashName;
  private final ItemReporter itemReporter;

      extends ImmutableEntry<K, V> {
    final int keyHash;
    final int valueHash;

    // All BiEntry instances are strongly reachable from owning HashBiMap through
    // "HashBiMap.hashTableKToV" and "BiEntry.nextInKToVBucket" references.
    // Under that assumption, the remaining references can be safely marked as @Weak.