*     in an {@code int}
   */
  public static double[] concat(double[]... arrays) {
    long length = 0;
    for (double[] array : arrays) {
      length += array.length;
    }
    double[] result = new double[checkNoOverflow(length)];
    int pos = 0;
    for (double[] array : arrays) {
      System.arraycopy(array, 0, result, pos, array.length);
      pos += array.length;
    }

   * b, c}}.
   *
   * @param arrays zero or more {@code boolean} arrays
   * @return a single array containing all the values from the source arrays, in order
   * @throws IllegalArgumentException if the total number of elements in {@code arrays} does not fit
   *     in an {@code int}
   */
  public static boolean[] concat(boolean[]... arrays) {
    long length = 0;
    for (boolean[] array : arrays) {

   * b, c}}.
   *
   * @param arrays zero or more {@code boolean} arrays
   * @return a single array containing all the values from the source arrays, in order
   * @throws IllegalArgumentException if the total number of elements in {@code arrays} does not fit
   *     in an {@code int}
   */
  public static boolean[] concat(boolean[]... arrays) {
    long length = 0;
    for (boolean[] array : arrays) {

   *     in an {@code int}
   */
  public static short[] concat(short[]... arrays) {
    long length = 0;
    for (short[] array : arrays) {
      length += array.length;
    }
    short[] result = new short[checkNoOverflow(length)];
    int pos = 0;
    for (short[] array : arrays) {
      System.arraycopy(array, 0, result, pos, array.length);
      pos += array.length;
    }
    return result;

   *     in an {@code int}
   */
  public static short[] concat(short[]... arrays) {
    long length = 0;
    for (short[] array : arrays) {
      length += array.length;
    }
    short[] result = new short[checkNoOverflow(length)];
    int pos = 0;
    for (short[] array : arrays) {
      System.arraycopy(array, 0, result, pos, array.length);
      pos += array.length;
    }
    return result;

   *     in an {@code int}
   */
  public static char[] concat(char[]... arrays) {
    long length = 0;
    for (char[] array : arrays) {
      length += array.length;
    }
    char[] result = new char[checkNoOverflow(length)];
    int pos = 0;
    for (char[] array : arrays) {
      System.arraycopy(array, 0, result, pos, array.length);
      pos += array.length;
    }
    return result;
  }

  private static void testSortDescending(byte[] input, byte[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    SignedBytes.sortDescending(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testSortDescending(
      byte[] input, int fromIndex, int toIndex, byte[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    SignedBytes.sortDescending(input, fromIndex, toIndex);

    return CompactHashSet.create();
  }

  /**
   * Returns a new array of the given length with the same type as a reference array.
   *
   * @param reference any array of the desired type
   * @param length the length of the new array
   */
  /*
   * The new array contains nulls, even if the old array did not. If we wanted to be accurate, we

   *     in an {@code int}
   */
  public static int[] concat(int[]... arrays) {
    long length = 0;
    for (int[] array : arrays) {
      length += array.length;
    }
    int[] result = new int[checkNoOverflow(length)];
    int pos = 0;
    for (int[] array : arrays) {
      System.arraycopy(array, 0, result, pos, array.length);
      pos += array.length;
    }
    return result;
  }

    return CompactHashSet.create();
  }

  /**
   * Returns a new array of the given length with the same type as a reference array.
   *
   * @param reference any array of the desired type
   * @param length the length of the new array
   */
  /*
   * The new array contains nulls, even if the old array did not. If we wanted to be accurate, we