*     #hasNext()}
   */
  @ParametricNullness
  E peek();

  /**
   * {@inheritDoc}
   *
   * <p>The objects returned by consecutive calls to {@link #peek()} then {@link #next()} are
   * guaranteed to be equal to each other.
   */
  @CanIgnoreReturnValue
  @Override
  @ParametricNullness
  E next();

  /**
   * {@inheritDoc}
   *

    int lastEntryIndex = -1;
    do {
      int entryIndex = next - 1;
      int entry = entries[entryIndex];
      if (getHashPrefix(entry, mask) == hashPrefix
          && Objects.equal(key, keys[entryIndex])
          && (values == null || Objects.equal(value, values[entryIndex]))) {
        int newNext = getNext(entry, mask);
        if (lastEntryIndex == -1) {
          // we need to update the root link from table[]

  /**
   * Compares the specified object to this multimap for equality.
   *
   * <p>Two {@code SetMultimap} instances are equal if, for each key, they contain the same values.
   * Equality does not depend on the ordering of keys or values.
   *
   * <p>An empty {@code SetMultimap} is equal to any other empty {@code Multimap}, including an
   * empty {@code ListMultimap}.
   */
  @Override

  /**
   * Compares the specified object to this multimap for equality.
   *
   * <p>Two {@code SetMultimap} instances are equal if, for each key, they contain the same values.
   * Equality does not depend on the ordering of keys or values.
   *
   * <p>An empty {@code SetMultimap} is equal to any other empty {@code Multimap}, including an
   * empty {@code ListMultimap}.
   */
  @Override

  @CheckForNull
  protected abstract Object handleInvocation(Object proxy, Method method, @Nullable Object[] args)
      throws Throwable;

  /**
   * By default delegates to {@link Object#equals} so instances are only equal if they are
   * identical. {@code proxy.equals(argument)} returns true if:
   *
   * <ul>
   *   <li>{@code proxy} and {@code argument} are of the same type

      assertFalse(
          "Should not contain key " + entry.getKey() + " mapped to value " + entry.getValue(),
          equal(getMap().get(entry.getKey()), entry.getValue()));
    }
  }

  private static boolean equal(@Nullable Object a, @Nullable Object b) {
    return a == b || (a != null && a.equals(b));
  }

  // This one-liner saves us from some ugly casts

    boolean errorNotThrown = false;
    try {
      SerializableTester.reserializeAndAssert(orig);
      errorNotThrown = true;
    } catch (AssertionFailedError error) {
      // expected
      assertContains("must be equal to the Object#hashCode", error.getMessage());
    }
    assertFalse(errorNotThrown);
  }

  public void testObjectWhichIsEqualButChangesClass() {

    boolean errorNotThrown = false;
    try {
      SerializableTester.reserializeAndAssert(orig);
      errorNotThrown = true;
    } catch (AssertionFailedError error) {
      // expected
      assertContains("must be equal to the Object#hashCode", error.getMessage());
    }
    assertFalse(errorNotThrown);
  }

  public void testObjectWhichIsEqualButChangesClass() {

      assertFalse(
          "Should not contain key " + entry.getKey() + " mapped to value " + entry.getValue(),
          equal(getMap().get(entry.getKey()), entry.getValue()));
    }
  }

  private static boolean equal(@Nullable Object a, @Nullable Object b) {
    return a == b || (a != null && a.equals(b));
  }

  // This one-liner saves us from some ugly casts

    int lastEntryIndex = -1;
    do {
      int entryIndex = next - 1;
      int entry = entries[entryIndex];
      if (getHashPrefix(entry, mask) == hashPrefix
          && Objects.equal(key, keys[entryIndex])
          && (values == null || Objects.equal(value, values[entryIndex]))) {
        int newNext = getNext(entry, mask);
        if (lastEntryIndex == -1) {
          // we need to update the root link from table[]