"Invalid URL host: \"[0000:0000:0000:0000:0000:0000:0000:0001:]\"",
    )
    assertInvalid(
      "http://[0000:0000:0000:0000:0000:0000:0000:0001::]",
      "Invalid URL host: \"[0000:0000:0000:0000:0000:0000:0000:0001::]\"",
    )
    assertInvalid(
      "http://[0000:0000:0000:0000:0000:0000:0000:0001:::]",
      "Invalid URL host: \"[0000:0000:0000:0000:0000:0000:0000:0001:::]\"",

      .isEqualTo(date("1950-01-01T00:00:00.000+0000").time)
    assertThat(Adapters.parseUtcTime("500101010000Z"))
      .isEqualTo(date("1950-01-01T01:00:00.000+0000").time)

    assertThat(Adapters.parseUtcTime("491231225959Z"))
      .isEqualTo(date("2049-12-31T22:59:59.000+0000").time)
    assertThat(Adapters.parseUtcTime("491231235959Z"))
      .isEqualTo(date("2049-12-31T23:59:59.000+0000").time)
  }

  return when {
    isMappedIpv4Address(address) -> address.sliceArray(12 until 16)
    else -> address
  }
}

/** Returns true for IPv6 addresses like `0000:0000:0000:0000:0000:ffff:XXXX:XXXX`. */
private fun isMappedIpv4Address(address: ByteArray): Boolean {
  if (address.size != 16) return false

  for (i in 0 until 10) {
    if (address[i] != 0.toByte()) return false
  }

    if (limit == -1L && source.exhausted()) return END_OF_DATA

    // Read the tag.
    val tagAndClass = source.readByte().toInt() and 0xff
    val tagClass = tagAndClass and 0b1100_0000
    val constructed = (tagAndClass and 0b0010_0000) == 0b0010_0000
    val tag =
      when (val tag0 = tagAndClass and 0b0001_1111) {
        0b0001_1111 -> readVariableLengthLong()
        else -> tag0.toLong()
      }

    return result
  }

  override fun toString(): String = "$tagClass/$tag"

  companion object {
    const val TAG_CLASS_UNIVERSAL = 0b0000_0000
    const val TAG_CLASS_APPLICATION = 0b0100_0000
    const val TAG_CLASS_CONTEXT_SPECIFIC = 0b1000_0000
    const val TAG_CLASS_PRIVATE = 0b1100_0000

    const val TAG_END_OF_CONTENTS = 0L
  }

    assertThat(cookie.matches("http://[::1]/".toHttpUrl())).isTrue()
  }

  @Test fun domainMatchesIpv6AddressWithCompression() {
    val cookie = parse("http://[0001:0000::]/".toHttpUrl(), "a=b; domain=0001:0000::")
    assertThat(cookie!!.domain).isEqualTo("1::")
    assertThat(cookie.matches("http://[1::]/".toHttpUrl())).isTrue()
  }

  @Test fun domainMatchesIpv6AddressWithIpv4Suffix() {

  }

  @Test fun readCodePointSet() {
    val buffer = Buffer()
    buffer.writeUtf8(
      """
      |  0221
      |  0234-024F
      |  0000-001F; [CONTROL CHARACTERS]
      |  007F; DELETE
      |
      """.trimMargin(),
    )

    val rangeList = buffer.readCodePointSet()
    assertEquals(
      listOf(
        0x0221..0x0221,

      randalcatSet = randalcatSet,
      lcatSet = lcatSet,
    )
  }

  /**
   * Reads a set of range lines like the following:
   *
   * ```
   *  0221
   *  0234-024F
   *  0000-001F; [CONTROL CHARACTERS]
   *  007F; DELETE
   * ```
   */
  fun readCodePointSet(path: Path): RangeListCodePointSet {
    fileSystem.source(path).buffer().use { source ->
      return source.readCodePointSet()
    }

    .build();
client.newCall(newYorkTimesRequest).enqueue(new Callback() {
  ...
});
```

Running this race over home WiFi shows the Times (`0002`) completes just slightly sooner than the Post (`0001`):

```
0001 https://www.washingtonpost.com/
0001 0.000 callStart
0002 https://www.nytimes.com/
0002 0.000 callStart
0002 0.010 dnsStart
0001 0.013 dnsStart
0001 0.022 dnsEnd
0002 0.019 dnsEnd

    stack.add(content)
    constructed = false // The enclosed object written in block() is not constructed.
    path += name
    try {
      block(content)
      constructedBit = if (constructed) 0b0010_0000 else 0
      constructed = true // The enclosing object is constructed.
    } finally {
      stack.removeAt(stack.size - 1)
      path.removeAt(path.size - 1)
    }

    val sink = sink()