throw AssertionError("Thread ${Thread.currentThread().name} MUST hold lock on $this")
    }
  }

  @Suppress("NOTHING_TO_INLINE")
  internal inline fun Any.assertThreadDoesntHoldLock() {
    if (assertionsEnabled && taskRunner.lock.isHeldByCurrentThread) {
      throw AssertionError("Thread ${Thread.currentThread().name} MUST NOT hold lock on $this")
    }
  }

 - **CacheConditionalHit**
 - ConnectionAcquired
 - ... Standard Events...
 - ResponseBodyEnd _(0 bytes)_
 - **CacheHit**
 - ConnectionReleased
 - CallEnd
 
## Cache directory

The cache directory must be exclusively owned by a single instance.

Deleting the cache when it is no longer needed can be done.  However this may delete the purpose of the cache
which is designed to persist between app restarts.

```kotlin

import java.io.IOException
import okhttp3.Protocol
import okio.BufferedSource

/**
 * [HTTP/2][Protocol.HTTP_2] only. Processes server-initiated HTTP requests on the client.
 * Implementations must quickly dispatch callbacks to avoid creating a bottleneck.
 *
 * While [onReset] may occur at any time, the following callbacks are expected in order,
 * correlated by stream ID.
 *
 *  * [onRequest]

        .build()
    assertFailsWith<IllegalStateException> {
      client.newCall(request).execute()
    }.also { expected ->
      assertThat(expected.message).isEqualTo(
        "network interceptor $interceptor must call proceed() exactly once",
      )
    }
  }

  @Test
  fun networkInterceptorsCannotCallProceedMultipleTimes() {
    server.enqueue(MockResponse())
    server.enqueue(MockResponse())

    val isMasked = b1 and B1_FLAG_MASK != 0
    if (isMasked == isClient) {
      // Masked payloads must be read on the server. Unmasked payloads must be read on the client.
      throw ProtocolException(
        if (isClient) {
          "Server-sent frames must not be masked."
        } else {
          "Client-sent frames must be masked."
        },
      )
    }

/**
 * A single attempt to connect to a remote server, including these steps:
 *
 *  * [TCP handshake][connectSocket]
 *  * Optional [CONNECT tunnels][connectTunnel]. When using an HTTP proxy to reach an HTTPS server
 *    we must send a `CONNECT` request, and handle authorization challenges from the proxy.
 *  * Optional [TLS handshake][connectTls].
 *
 * Each step may fail. If a retry is possible, a new instance is created with the next plan, which

    programmatically (with `new Response.Builder()`) you must now always supply
    a message. An empty string `""` is permitted. This value was never null on
    responses returned by OkHttp itself, and it was an old mistake to permit
    application code to omit a message.

 *  The challenge's scheme and realm are now non-null. If you are calling
    `new Challenge(scheme, realm)` you must provide non-null values. These were

  public CustomCipherSuites() throws GeneralSecurityException {
    // Configure cipher suites to demonstrate how to customize which cipher suites will be used for
    // an OkHttp request. In order to be selected a cipher suite must be included in both OkHttp's
    // connection spec and in the SSLSocket's enabled cipher suites array. Most applications should
    // not customize the cipher suites list.
    List<CipherSuite> customCipherSuites = asList(

 * and a fixed number of values. Each key must match the regex `[a-z0-9_-]{1,64}`. Values are byte
 * sequences, accessible as streams or files. Each value must be between `0` and `Int.MAX_VALUE`
 * bytes in length.
 *
 * The cache stores its data in a directory on the filesystem. This directory must be exclusive to

 * part is particularly large or if the underlying source is particularly slow, the [nextPart] call
 * may be slow!
 *
 * Closing a part **does not** close this multipart reader; callers must explicitly close this with
 * [close].
 *
 * [rfc_2046]: http://www.ietf.org/rfc/rfc2046.txt
 */
class MultipartReader
  @Throws(IOException::class)
  constructor(
    private val source: BufferedSource,