This particularly-subtle bug was caused by us assigning each `OkHttpClient` instance its own
    `NullProxySelector` when an explicit proxy is configured. But we don't share connections when
    the proxy selectors are different. Ugh!


## Version 4.2.0

_2019-09-10_

 *  New: API to decode a certificate and private key to create a `HeldCertificate`. This accepts a

  /** Returns the connection to use, which might be different from [connection]. */
  override fun handleSuccess(): RealConnection {
    user.updateRouteDatabaseAfterSuccess(route)

    val connection = this.connection!!
    user.connectionConnectEnd(connection, route)

    // If we raced another call connecting to this host, coalesce the connections. This makes for
    // 3 different lookups in the connection pool!

        return null
      }

      HTTP_MISDIRECTED_REQUEST -> {
        // OkHttp can coalesce HTTP/2 connections even if the domain names are different. See
        // RealConnection.isEligible(). If we attempted this and the server returned HTTP 421, then
        // we can retry on a different connection.
        val requestBody = userResponse.request.body
        if (requestBody != null && requestBody.isOneShot()) {
          return null

      }

    val trustManager = get().platformTrustManager()
    val sslContext = get().newSSLContext()
    sslContext.init(null, null, null)

    // new client, may share all same fields but likely different connection pool
    assertNotSame(
      client.routeDatabase,
      OkHttpClient.Builder()
        .build()
        .routeDatabase,
    )

    // same client with no change affecting route db

    }

  /**
   * A callback to be invoked each time the dispatcher becomes idle (when the number of running
   * calls returns to zero).
   *
   * Note: The time at which a [call][Call] is considered idle is different depending on whether it
   * was run [asynchronously][Call.enqueue] or [synchronously][Call.execute]. Asynchronous calls
   * become idle after the [onResponse][Callback.onResponse] or [onFailure][Callback.onFailure]

      .assertCode(200)
      .assertBody("A")
    val request1ReceivedAt = System.currentTimeMillis()
    assertThat(server.takeRequest().headers["If-None-Match"]).isNull()

    // Hit that stored response. It's different, but Vary says it doesn't matter.
    Thread.sleep(10) // Make sure the timestamps are unique.
    val cacheHit =
      executeSynchronously(
        "/",
        "Accept-Language",
        "en-US",

    without stabilizing these new APIs first.

    Do not use these experimental APIs in modules that may be executed using a version of OkHttp
    different from the version that the module was compiled with. Do not use them in published
    libraries. Do not use them if you aren't willing to track changes to them.

 *  Breaking: Drop support for Kotlin Multiplatform.

          val newStream = Http2Stream(streamId, this@Http2Connection, false, inFinished, headers)
          lastGoodStreamId = streamId
          streams[streamId] = newStream

          // Use a different task queue for each stream because they should be handled in parallel.
          taskRunner.newQueue().execute("$connectionName[$streamId] onStream") {
            try {
              listener.onStream(newStream)

  }

  /**
   * When the server returns a full response body we will store it and return it regardless of what
   * its Last-Modified date is. This behavior was different prior to OkHttp 3.5 when we would prefer
   * the response with the later Last-Modified date.
   *
   * https://github.com/square/okhttp/issues/2886
   */
  @Test
  fun serverReturnsDocumentOlderThanCache() {

    a.setString(1, "a2")
    a.commit()
    assertAbsent("a")
  }

  /**
   * Each read sees a snapshot of the file at the time read was called. This means that two reads of
   * the same key can see different data.
   */
  @ParameterizedTest
  @ArgumentsSource(FileSystemParamProvider::class)
  fun readAndWriteOverlapsMaintainConsistency(parameters: Pair<FileSystem, Boolean>) {
    setUp(parameters.first, parameters.second)