/**
     * Sets the authenticator used to respond to challenges from origin servers. Use
     * [proxyAuthenticator] to set the authenticator for proxy servers.
     *
     * If unset, the [no authentication will be attempted][Authenticator.NONE].
     */
    fun authenticator(authenticator: Authenticator) =
      apply {
        this.authenticator = authenticator
      }

## Version 3.4.2

_2016-11-03_

 *  Fix: Recover gracefully when an HTTP/2 connection is shutdown. We had a
    bug where shutdown HTTP/2 connections were considered usable. This caused
    infinite loops when calls attempted to recover.


## Version 3.4.1

_2016-07-10_

 *  **Fix a major bug in encoding HTTP headers.** In 3.4.0 and 3.4.0-RC1 OkHttp
    had an off-by-one bug in our HPACK encoder. This bug could have caused the

    }.also { expected ->
      assertThat(expected.errorCode).isEqualTo(ErrorCode.REFUSED_STREAM)
    }
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0) // New connection.

    // Second call attempts the pooled connection, and it fails. Then it retries a new route which
    // succeeds.
    val response2 = client.newCall(request).execute()
    assertThat(response2.body.string()).isEqualTo("abc")

 * stores information-per-URL will need to either canonicalize manually, or suffer unnecessary
 * redundancy for such URLs.
 *
 * Because they don't attempt canonical form, these classes are surprisingly difficult to use
 * securely. Suppose you're building a webservice that checks that incoming paths are prefixed

  fun recoverFromInitializationFailure(parameters: Pair<FileSystem, Boolean>) {
    setUp(parameters.first, parameters.second)
    // Add an uncommitted entry. This will get detected on initialization, and the cache will
    // attempt to delete the file. Do not explicitly close the cache here so the entry is left as
    // incomplete.
    val creator = cache.edit("k1")!!
    creator.newSink(0).buffer().use {
      it.writeUtf8("Hello")
    }