}
  }

  /** Returns the product of {@code n1} exclusive through {@code n2} inclusive. */
  @SuppressWarnings("UseCorrectAssertInTests") // TODO(b/345814817): Remove or convert assertion.
  private static BigInteger oldSlowFactorial(int n1, int n2) {
    assert n1 <= n2;
    if (IntMath.log2(n2, CEILING) * (n2 - n1) < Long.SIZE - 1) {
      // the result will definitely fit into a long

      val i = queue.iterator()
      while (i.hasNext()) {
        val signingCert = i.next() as X509Certificate
        if (verifySignature(toVerify, signingCert, result.size - 1)) {
          i.remove()
          result.add(signingCert)
          continue@followIssuerChain
        }
      }

      // We've reached the end of the chain. If any cert in the chain is trusted, we're done.

      return standardContains(object);
    }

    @Override
    public boolean containsAll(Collection<?> collection) {
      return standardContainsAll(collection);
    }

    @Override
    public boolean remove(Object object) {
      return standardRemove(object);
    }

    @Override
    public boolean removeAll(Collection<?> collection) {
      return standardRemoveAll(collection);
    }

    @Override

    public boolean isEmpty() {
      return standardIsEmpty();
    }

    @Override
    public Iterator<E> iterator() {
      return standardIterator();
    }

    @Override
    public boolean remove(@Nullable Object object) {
      return standardRemove(object);
    }

    @Override
    public boolean removeAll(Collection<?> collection) {
      return standardRemoveAll(collection);
    }

 *       {@code NullPointerTester} would need are not available) and in case of <a
 *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
 * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */

      return standardContains(object);
    }

    @Override
    public boolean containsAll(Collection<?> collection) {
      return standardContainsAll(collection);
    }

    @Override
    public boolean remove(Object object) {
      return standardRemove(object);
    }

    @Override
    public boolean removeAll(Collection<?> collection) {
      return standardRemoveAll(collection);
    }

    @Override

  }

  public void testRemoveUnsupported() {
    Multiset<String> multiset = new NoRemoveMultiset<>();
    multiset.add("a");
    assertThrows(UnsupportedOperationException.class, () -> multiset.remove("a"));
    assertTrue(multiset.contains("a"));
  }

  private static class NoRemoveMultiset<E extends @Nullable Object> extends AbstractMultiset<E>
      implements Serializable {

    /**
     * 
     * @param flag
     * @return whether flag is set
     */
    public boolean isFlagSet ( int flag ) {
        return ( this.flags & flag ) == flag;
    }


    /**
     * Remove flag
     * 
     * @param flag
     */
    public void unsetFlag ( int flag ) {
        this.flags &= ~flag;
    }


    /**
     * Set flag
     * 
     * @param flag
     */

 *       {@code NullPointerTester} would need are not available) and in case of <a
 *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
 * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */

 *       {@code NullPointerTester} would need are not available) and in case of <a
 *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
 * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */