*  Fix: Forbid spaces in header names.
 *  Fix: Don't offer to do gzip if the request is partial.
 *  Fix: MockWebServer is now usable with JUnit 5. That update [broke the rules][junit_5_rules].
 *  New: Support `Expect: 100-continue` as a request header. Callers can use this header to
    pessimistically hold off on transmitting a request body until a server gives the go-ahead.

With fast fallback, OkHttp attempts to connect to multiple web servers concurrently. It keeps whichever route connects first and cancels all of the others. Its rules are:

 * Prefer to alternate IP addresses from different address families, (IPv6 / IPv4), starting with IPv6.
 * Don't start a new attempt until 250 ms after the most recent attempt was started.

 */
@Timeout(30)
class FastFallbackTest {
  @RegisterExtension
  val clientTestRule = OkHttpClientTestRule()

  // Don't use JUnit 5 test rules for these; otherwise we can't bind them to a single local IP.
  private lateinit var localhostIpv4: InetAddress
  private lateinit var localhostIpv6: InetAddress
  private lateinit var serverIpv4: MockWebServer

      }
      sink.flush()
    }
  }

  /**
   * Send a connection-level ping to the peer. `ack` indicates this is a reply. The data in
   * `payload1` and `payload2` opaque binary, and there are no rules on the content.
   */
  @Throws(IOException::class)
  fun ping(
    ack: Boolean,
    payload1: Int,
    payload2: Int,
  ) {
    this.withLock {
      if (closed) throw IOException("closed")

    /** HTTP/2 only. */
    fun ackSettings()

    /**
     * Read a connection-level ping from the peer. `ack` indicates this is a reply. The data
     * in `payload1` and `payload2` opaque binary, and there are no rules on the content.
     */
    fun ping(
      ack: Boolean,
      payload1: Int,
      payload2: Int,
    )

    /**
     * The peer tells us to stop creating streams. It is safe to replay streams with

    val executeAtNanos = System.nanoTime()
    assertFailsWith<StreamResetException> {
      call.execute()
    }.also { expected ->
      assertThat(expected.message).isEqualTo(
        "stream was reset: PROTOCOL_ERROR",
      )
    }
    val elapsedUntilFailure = System.nanoTime() - executeAtNanos
    assertThat(TimeUnit.NANOSECONDS.toMillis(elapsedUntilFailure).toDouble())
      .isCloseTo(1000.0, 250.0)

class HpackTest {
  private val bytesIn = Buffer()
  private var hpackReader: Hpack.Reader? = null
  private val bytesOut = Buffer()
  private var hpackWriter: Hpack.Writer? = null

  @BeforeEach
  fun reset() {
    hpackReader = newReader(bytesIn)
    hpackWriter = Hpack.Writer(4096, false, bytesOut)
  }

  /**
   * Variable-length quantity special cases strings which are longer than 127 bytes.  Values such as

      if (pos == limit) {
        // Empty path: keep the base path as-is.
        return
      }
      val c = input[pos]
      if (c == '/' || c == '\\') {
        // Absolute path: reset to the default "/".
        encodedPathSegments.clear()
        encodedPathSegments.add("")
        pos++
      } else {
        // Relative path: clear everything after the last '/'.

# no rules should be needed...

  /** Inflates [buffer] in place as described in RFC 7692 section 7.2.2. */
  @Throws(IOException::class)
  fun inflate(buffer: Buffer) {
    require(deflatedBytes.size == 0L)

    if (noContextTakeover) {
      inflater.reset()
    }

    deflatedBytes.writeAll(buffer)
    deflatedBytes.writeInt(OCTETS_TO_ADD_BEFORE_INFLATION)

    val totalBytesToRead = inflater.bytesRead + deflatedBytes.size