String[] suffix = {"f", "g"};
      String[] all = new String[elements.length + suffix.length];
      System.arraycopy(elements, 0, all, 0, elements.length);
      System.arraycopy(suffix, 0, all, elements.length, suffix.length);
      return ImmutableList.copyOf(all).subList(0, elements.length);
    }
  }

  public static class ImmutableListTailSubListGenerator extends TestStringListGenerator {

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

  /**

    checkNotNull(separator);
    if (array.length == 0) {
      return "";
    }

    // For pre-sizing a builder, just get the right order of magnitude
    StringBuilder builder = new StringBuilder(array.length * (3 + separator.length()));
    builder.append(toInt(array[0]));
    for (int i = 1; i < array.length; i++) {
      builder.append(separator).append(toString(array[i]));
    }

  }

  public void testNewReferenceArray_withLength() throws Exception {
    int length = 42;
    AtomicReferenceArray<String> refArray = Atomics.newReferenceArray(length);
    for (int i = 0; i < length; ++i) {
      assertEquals(null, refArray.get(i));
    }
    assertThrows(IndexOutOfBoundsException.class, () -> refArray.get(length));
  }

  public void testNewReferenceArray_withNegativeLength() throws Exception {

  }

  public void testNewReferenceArray_withLength() throws Exception {
    int length = 42;
    AtomicReferenceArray<String> refArray = Atomics.newReferenceArray(length);
    for (int i = 0; i < length; ++i) {
      assertEquals(null, refArray.get(i));
    }
    assertThrows(IndexOutOfBoundsException.class, () -> refArray.get(length));
  }

  public void testNewReferenceArray_withNegativeLength() throws Exception {

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

  /**

    }

    @Override
    public int indexIn(CharSequence sequence) {
      return (sequence.length() == 0) ? -1 : 0;
    }

    @Override
    public int indexIn(CharSequence sequence, int start) {
      int length = sequence.length();
      checkPositionIndex(start, length);
      return (start == length) ? -1 : start;
    }

    @Override
    public int lastIndexIn(CharSequence sequence) {

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

  }

  /**
   * Shortens the last frame from its original length to `length`. This will cause the peer to
   * close the socket as soon as this frame has been written; otherwise the peer stays open until
   * explicitly closed.
   */
  fun truncateLastFrame(length: Int): Http2Writer {
    val lastFrame = outFrames.removeAt(outFrames.size - 1)
    require(length < bytesOut.size - lastFrame.start)

  public void testLength() {
    assertThat(ImmutableIntArray.of().length()).isEqualTo(0);
    assertThat(ImmutableIntArray.of(0).length()).isEqualTo(1);
    assertThat(ImmutableIntArray.of(0, 1, 3).length()).isEqualTo(3);
    assertThat(ImmutableIntArray.of(0, 1, 3).subArray(1, 1).length()).isEqualTo(0);
    assertThat(ImmutableIntArray.of(0, 1, 3).subArray(1, 2).length()).isEqualTo(1);
  }

  public void testIsEmpty() {