* method. It is an efficient relative that also will pad the left side so
     * that the result is <code>size</code> digits.
     *
     * @param val the integer value to convert to hexadecimal
     * @param size the desired length of the resulting hex string (will be left-padded with zeros)
     * @return a hexadecimal string representation of the value, padded to the specified size
     */

    INSTANCE;

    @Override
    public int compare(byte[] left, byte[] right) {
      int minLength = Math.min(left.length, right.length);
      for (int i = 0; i < minLength; i++) {
        int result = Byte.compare(left[i], right[i]);
        if (result != 0) {
          return result;
        }
      }
      return left.length - right.length;
    }

    @Override
    public String toString() {

    // directory with a cycle,
    // /root
    //    /left
    //       /[sibling -> right]
    //    /right
    //       /[sibling -> left]
    Path root = createTempDirectory("ClassPathTest");
    try {
      Path left = createDirectory(root.resolve("left"));
      createFile(left.resolve("some.txt"));

      Path right = createDirectory(root.resolve("right"));

 * without changing the iterator's state, using the {@link #hasNext} method. But many data sources,
 * such as {@link java.io.Reader#read()}, do not expose this information; the only way to discover
 * whether there is any data left is by trying to retrieve it. These types of data sources are
 * ordinarily difficult to write iterators for. But using this class, one must implement only the

            Optional.empty<T>()
        )
    }.reduce { acc, next ->
        acc.zip(next) { left, right ->
            when {
                left.isPresent -> {
                    require(!right.isPresent) {
                        "Expected at most one provider to be present"
                    }
                    left
                }
                else -> right
            }
        }

          push(stack, newAccum);
        }
        push(stack, collector.supplier().get());
        while (stack.size() > 1) {
          A right = pop(stack);
          A left = pop(stack);
          push(stack, collector.combiner().apply(left, right));
        }
        return pop(stack);
      }

      <E extends @Nullable Object> void push(List<E> stack, E value) {
        stack.add(value);
      }

    this.function = checkNotNull(function);
    this.ordering = checkNotNull(ordering);
  }

  @Override
  public int compare(@ParametricNullness F left, @ParametricNullness F right) {
    return ordering.compare(function.apply(left), function.apply(right));
  }

  @Override
  public boolean equals(@Nullable Object object) {
    if (object == this) {
      return true;
    }

        Iterables.toArray(comparators, (Comparator<? super T>[]) new Comparator<?>[0]);
  }

  @Override
  public int compare(@ParametricNullness T left, @ParametricNullness T right) {
    for (int i = 0; i < comparators.length; i++) {
      int result = comparators[i].compare(left, right);
      if (result != 0) {
        return result;
      }
    }
    return 0;
  }

  @Override

    this.function = checkNotNull(function);
    this.ordering = checkNotNull(ordering);
  }

  @Override
  public int compare(@ParametricNullness F left, @ParametricNullness F right) {
    return ordering.compare(function.apply(left), function.apply(right));
  }

  @Override
  public boolean equals(@Nullable Object object) {
    if (object == this) {
      return true;
    }

    this(Maps.indexMap(valuesInOrder));
  }

  ExplicitOrdering(ImmutableMap<T, Integer> rankMap) {
    this.rankMap = rankMap;
  }

  @Override
  public int compare(T left, T right) {
    return rank(left) - rank(right); // safe because both are nonnegative
  }

  private int rank(T value) {
    Integer rank = rankMap.get(value);
    if (rank == null) {
      throw new IncomparableValueException(value);