* Section 7.2.1.2. The iteration order follows the lexicographical order. This means that the
   * first permutation will be in ascending order, and the last will be in descending order.
   *
   * <p>Duplicate elements are considered equal. For example, the list [1, 1] will have only one
   * permutation, instead of two. This is why the elements have to implement {@link Comparable}.

			if p.buf[bufIdx] == nil {
				// Reading first time on this disk, hence the buffer needs to be allocated.
				// Subsequent reads will reuse this buffer.
				p.buf[bufIdx] = make([]byte, p.shardSize)
			}
			// For the last shard, the shardsize might be less than previous shard sizes.
			// Hence the following statement ensures that the buffer size is reset to the right size.
			p.buf[bufIdx] = p.buf[bufIdx][:p.shardSize]

   * @param element the element to append to the end
   * @return an array whose size is one larger than {@code array}, with the same contents as {@code
   *     array}, plus {@code element} occupying the last position.
   */
  public static <T extends @Nullable Object> T[] concat(T[] array, @ParametricNullness T element) {
    T[] result = Arrays.copyOf(array, array.length + 1);
    result[array.length] = element;

    }

    public void testLast() {
      for (List<Integer> contents : SAMPLE_INPUTS) {
        C filtered = filter(createUnfiltered(contents), EVEN);

        try {
          Integer first = filtered.last();
          assertFalse(filtered.isEmpty());
          assertEquals(Ordering.natural().max(filtered), first);
        } catch (NoSuchElementException e) {
          assertTrue(filtered.isEmpty());
        }
      }

  @SuppressWarnings("unchecked")
  @Override
  @CheckForNull
  public V get(@CheckForNull Object key) {
    Object result = get(hashTable, alternatingKeysAndValues, size, 0, key);
    /*
     * We can't simply cast the result of `RegularImmutableMap.get` to V because of a bug in our
     * nullness checker (resulting from https://github.com/jspecify/checker-framework/issues/8).
     */
    if (result == null) {
      return null;

     * just to be safe.
     *
     * The real purpose of this test is to produce a TSAN failure if MapIteratorCache is unsafe for
     * reads from multiple threads -- unsafe, in fact, even in the absence of a concurrent write.
     * The specific problem we had was unsafe reads of lastEntryReturnedBySomeIterator. (To fix the
     * problem, we've since marked that field as volatile.)
     *

    return result;
  }

  /**
   * Returns the {@code char} nearest in value to {@code value}.
   *
   * @param value any {@code long} value
   * @return the same value cast to {@code char} if it is in the range of the {@code char} type,
   *     {@link Character#MAX_VALUE} if it is too large, or {@link Character#MIN_VALUE} if it is too
   *     small
   */

    return result;
  }

  /**
   * Returns the {@code short} nearest in value to {@code value}.
   *
   * @param value any {@code long} value
   * @return the same value cast to {@code short} if it is in the range of the {@code short} type,
   *     {@link Short#MAX_VALUE} if it is too large, or {@link Short#MIN_VALUE} if it is too small
   */
  public static short saturatedCast(long value) {

    return result;
  }

  /**
   * Returns the {@code short} nearest in value to {@code value}.
   *
   * @param value any {@code long} value
   * @return the same value cast to {@code short} if it is in the range of the {@code short} type,
   *     {@link Short#MAX_VALUE} if it is too large, or {@link Short#MIN_VALUE} if it is too small
   */
  public static short saturatedCast(long value) {

  /*
   * LegacyConverter violates the contract of Converter by allowing its doForward and doBackward
   * methods to accept null. We could avoid having unchecked casts in Converter.java itself if we
   * could perform a cast to LegacyConverter, but we can't because it's an internal-only class.
   *
   * TODO(cpovirk): So make it part of the open-source build, albeit package-private there?
   *