h[1] = h[2] = h[3] = 0;
        return h;
    }

    /**
     * Concatenates multiple byte arrays into a single array.
     */
    private static byte[] concat(byte[]... arrays) {
        int total = 0;
        for (byte[] a : arrays) {
            total += a.length;
        }
        byte[] res = new byte[total];
        int off = 0;
        for (byte[] a : arrays) {

      Double[] suffix = {86.0, 99.0};
      Double[] all = concat(concat(prefix, elements), suffix);
      return makeArray(all).subArray(2, elements.length + 2).asList();
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // used only from suite
  @AndroidIncompatible
  private static Double[] concat(Double[] a, Double[] b) {
    return ObjectArrays.concat(a, b, Double.class);
  }

  @J2ktIncompatible

      Byte[] prefix = {Byte.MIN_VALUE, Byte.MAX_VALUE};
      Byte[] suffix = {(byte) 86, (byte) 99};
      Byte[] all = concat(concat(prefix, elements), suffix);
      return asList(all).subList(2, elements.length + 2);
    }
  }

  private static Byte[] concat(Byte[] left, Byte[] right) {
    Byte[] result = new Byte[left.length + right.length];
    System.arraycopy(left, 0, result, 0, left.length);

      Long[] prefix = {Long.MIN_VALUE, Long.MAX_VALUE};
      Long[] suffix = {86L, 99L};
      Long[] all = concat(concat(prefix, elements), suffix);
      return asList(all).subList(2, elements.length + 2);
    }
  }

  private static Long[] concat(Long[] left, Long[] right) {
    Long[] result = new Long[left.length + right.length];
    System.arraycopy(left, 0, result, 0, left.length);

    assertThat(Chars.concat()).isEqualTo(EMPTY);
    assertThat(Chars.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Chars.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Chars.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Chars.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Chars.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);
    assertThat(Chars.concat(ARRAY1, ARRAY1, ARRAY1))

    assertThat(CharSource.concat(ImmutableList.of(c1, c2, c3)).read()).isEqualTo(expected);
    assertThat(CharSource.concat(c1, c2, c3).read()).isEqualTo(expected);
    assertThat(CharSource.concat(ImmutableList.of(c1, c2, c3).iterator()).read())
        .isEqualTo(expected);
    assertFalse(CharSource.concat(c1, c2, c3).isEmpty());

    CharSource emptyConcat = CharSource.concat(CharSource.empty(), CharSource.empty());

      Float[] prefix = {Float.MIN_VALUE, Float.MAX_VALUE};
      Float[] suffix = {86.0f, 99.0f};
      Float[] all = concat(concat(prefix, elements), suffix);
      return asList(all).subList(2, elements.length + 2);
    }
  }

  private static Float[] concat(Float[] left, Float[] right) {
    Float[] result = new Float[left.length + right.length];
    System.arraycopy(left, 0, result, 0, left.length);

      Float[] prefix = {Float.MIN_VALUE, Float.MAX_VALUE};
      Float[] suffix = {86.0f, 99.0f};
      Float[] all = concat(concat(prefix, elements), suffix);
      return asList(all).subList(2, elements.length + 2);
    }
  }

  private static Float[] concat(Float[] left, Float[] right) {
    Float[] result = new Float[left.length + right.length];
    System.arraycopy(left, 0, result, 0, left.length);

      Integer[] prefix = {Integer.MIN_VALUE, Integer.MAX_VALUE};
      Integer[] suffix = {(int) 86, (int) 99};
      Integer[] all = concat(concat(prefix, elements), suffix);
      return asList(all).subList(2, elements.length + 2);
    }
  }

  private static Integer[] concat(Integer[] left, Integer[] right) {
    Integer[] result = new Integer[left.length + right.length];
    System.arraycopy(left, 0, result, 0, left.length);

    assertArrayEquals(expected, ByteSource.concat(ImmutableList.of(b1, b2, b3)).read());
    assertArrayEquals(expected, ByteSource.concat(b1, b2, b3).read());
    assertArrayEquals(expected, ByteSource.concat(ImmutableList.of(b1, b2, b3).iterator()).read());
    assertEquals(expected.length, ByteSource.concat(b1, b2, b3).size());
    assertFalse(ByteSource.concat(b1, b2, b3).isEmpty());