assertFalse(
        "multiset.entrySet() contains a non-entry", getMultiset().entrySet().contains(e0()));
  }

  public void testEntrySet_twice() {
    assertEquals(
        "calling multiset.entrySet() twice returned unequal sets",
        getMultiset().entrySet(),
        getMultiset().entrySet());
  }

  @CollectionSize.Require(ZERO)
  public void testEntrySet_hashCode_size0() {

    final ImmutableList<Timeout> timeouts;

    TimeoutsToUse(Timeout... timeouts) {
      this.timeouts = ImmutableList.copyOf(timeouts);
    }
  }

  /** Possible outcomes of calling any of the methods under test. */
  private enum Outcome {

    /** The method returned normally and is either void or returned true. */
    SUCCESS,

    /** The method returned false. */
    FAILURE,

   * <p>The returned object is serializable if {@code supplier} is serializable.
   *
   * @param supplier the supplier to be used for loading values; must never return {@code null}
   * @return a cache loader that loads values by calling {@link Supplier#get}, irrespective of the
   *     key
   */
  public static <V> CacheLoader<Object, V> from(Supplier<V> supplier) {
    return new SupplierToCacheLoader<>(supplier);
  }

  @CanIgnoreReturnValue
  @CheckForNull
  V forcePut(@ParametricNullness K key, @ParametricNullness V value);

  // Bulk Operations

  /**
   * {@inheritDoc}
   *
   * <p><b>Warning:</b> the results of calling this method may vary depending on the iteration order
   * of {@code map}.
   *
   * @throws IllegalArgumentException if an attempt to {@code put} any entry fails. Note that some

    assertEquals(20, counter.getCount());
    assertEquals(-1, counter.read(new byte[30]));
    assertEquals(20, counter.getCount());
  }

  @SuppressWarnings("CheckReturnValue") // calling read() to skip a byte
  public void testMark() throws Exception {
    assertTrue(counter.markSupported());
    assertEquals(10, counter.read(new byte[10]));
    assertEquals(10, counter.getCount());
    counter.mark(5);

      this.className = checkNotNull(className);
    }

    /**
     * Configures the {@link ToStringHelper} so {@link #toString()} will ignore properties with null
     * value. The order of calling this method, relative to the {@code add()}/{@code addValue()}
     * methods, is not significant.
     *
     * @since 18.0 (since 12.0 as {@code Objects.ToStringHelper.omitNullValues()}).
     */

      int j = findNextJ();
      if (j == -1) {
        nextPermutation = null;
        return;
      }
      /*
       * requireNonNull is safe because we don't clear nextPermutation until we're done calling this
       * method.
       */
      requireNonNull(nextPermutation);

      int l = findNextL(j);
      Collections.swap(nextPermutation, j, l);
      int n = nextPermutation.size();

    return getMultiset().setCount(element, getMultiset().count(element), count);
  }

  private void assertSetCountNegativeOldCount() {
    try {
      getMultiset().setCount(e3(), -1, 1);
      fail("calling setCount() with a negative oldCount should throw IllegalArgumentException");
    } catch (IllegalArgumentException expected) {
    }
  }

  // Negative oldCount.

  @CollectionFeature.Require(SUPPORTS_ADD)

   * initialization; we can't put this in the constructor because, in the case where futures are
   * already complete, we would not initialize the subclass before calling {@link
   * #collectValueFromNonCancelledFuture}. As this is called after the subclass is constructed,
   * we're guaranteed to have properly initialized the subclass.
   */
  final void init() {
    /*

                  throw new IllegalArgumentException("Multiple values for key: " + v1 + ", " + v2);
                }),
        (accum, t) -> {
          /*
           * We assign these to variables before calling checkNotNull to work around a bug in our
           * nullness checker.
           */
          K key = keyFunction.apply(t);
          V newValue = valueFunction.apply(t);
          accum.put(