the request already contains an `Accept` header.

 *  Fix: Don't crash with a `NullPointerException` if a server sends a close while we're sending a
    ping. OkHttp had a race condition bug.


## Version 4.6.0

_2020-04-28_

 *  Fix: Follow HTTP 307 and 308 redirects on methods other than GET and POST. We're reluctant to

    for a graceful shutdown before it performs an abrupt shutdown.

 *  Fix: Honor `RequestBody.isOneShot()` in `MultipartBody`

 *  Fix in `okhttp-coroutines`: Don't leak response bodies in `executeAsync()`. We had a bug where
    we didn't call `Response.close()` if the coroutine was canceled before its response was
    returned.

 *  Upgrade: [Okio 3.9.0][okio_3_9_0].

 *  Upgrade: [Kotlin 1.9.23][kotlin_1_9_23].

    }.also { expected ->
      assertThat(expected.message).isEqualTo("Too many follow-up requests: 21")
    }
  }

  /**
   * We had a bug where we were passing a null route to the authenticator.
   * https://github.com/square/okhttp/issues/3809
   */
  @Test
  fun authenticateWithNoConnection() {
    server.enqueue(
      MockResponse(

    Thread.sleep(500)
    server.send("Hello, WebSockets!")
    clientListener.assertTextMessage("Hello, WebSockets!")
    closeWebSockets(webSocket, server)
  }

  /**
   * We had a bug where web socket connections were leaked if the HTTP connection upgrade was not
   * successful. This test confirms that connections are released back to the connection pool!
   * https://github.com/square/okhttp/issues/4258
   */

      val reference = references[i]

      if (reference.get() != null) {
        i++
        continue
      }

      // We've discovered a leaked call. This is an application bug.
      val callReference = reference as CallReference
      val message =
        "A connection to ${connection.route().address.url} was leaked. " +
          "Did you forget to close a response body?"

    assertThat(response3.body.string()).isEqualTo("def")
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(1) // New connection.
  }

  /**
   * We had a bug where we'd perform infinite retries of route that fail with connection shutdown
   * errors. The problem was that the logic that decided whether to reuse a route didn't track

    Assumptions.assumeFalse(windows) // Can't deleteContents while the journal is open.

    filesystem.deleteRecursively(cacheDir)
    assertThat(cache["a"]).isNull()
  }

  /**
   * We had a long-lived bug where [DiskLruCache.trimToSize] could infinite loop if entries
   * being edited required deletion for the operation to complete.
   */
  @ParameterizedTest
  @ArgumentsSource(FileSystemParamProvider::class)