private var lastTimestampNs: Long? = null

  /** Confirm that the thread does not hold a lock on `lock` during the callback. */
  fun forbidLock(lock: Any) {
    forbiddenLocks.add(lock)
  }

  /**
   * Removes recorded events up to (and including) an event is found whose class equals [eventClass]
   * and returns it.
   */
  fun <T : ConnectionEvent> removeUpToEvent(eventClass: Class<T>): T {

from your test's `tearDown()`.

### API

#### MockResponse

Mock responses default to an empty response body and a `200` status code.
You can set a custom body with a string, input stream or byte array. Also
add headers with a fluent builder API.

```java
MockResponse response = new MockResponse()
    .addHeader("Content-Type", "application/json; charset=utf-8")
    .addHeader("Cache-Control", "no-cache")
    .setBody("{}");

      if (n > Int.MAX_VALUE - deltaN) return false // Prevent overflow.
      n += deltaN
      i %= (codePoints.size + 1)

      if (n > 0x10ffff) return false // Not a valid code point.

      codePoints.add(i, n)

      i++
    }

    for (codePoint in codePoints) {
      result.writeUtf8CodePoint(codePoint)
    }

    return true
  }

  /** Returns a new bias. */
  private fun adapt(

    val base = parse("http://host/a/b/c")

    // Add a string with zero slashes: resulting URL gains one slash.
    assertThat(base.newBuilder().addPathSegments("").build().encodedPath)
      .isEqualTo("/a/b/c/")
    assertThat(base.newBuilder().addPathSegments("d").build().encodedPath)
      .isEqualTo("/a/b/c/d")

    // Add a string with one slash: resulting URL gains two slashes.

    return result
  }

  fun acquireConnectionNoEvents(connection: RealConnection) {
    connection.lock.assertHeld()

    check(this.connection == null)
    this.connection = connection
    connection.calls.add(CallReference(this, callStackTrace))
  }

  /**
   * Releases resources held with the request or response of [exchange]. This should be called when

      chain: Array<X509Certificate>,
      authType: String,
    ) {
      calls.add("checkClientTrusted " + certificatesToString(chain))
    }

    override fun checkServerTrusted(
      chain: Array<X509Certificate>,
      authType: String,
    ) {
      calls.add("checkServerTrusted " + certificatesToString(chain))
    }

        .build()

    val client = OkHttpClient.Builder()
        .sslSocketFactory(clientCertificates.sslSocketFactory(), clientCertificates.trustManager)
        .build()
    ```

 *  New: Add `cacheHit`, `cacheMiss`, and `cacheConditionalHit()` events to `EventListener`. Use
    these in logs, metrics, and even test cases to confirm your cache headers are configured as
    expected.

    val headers =
      Headers.Builder()
        .add("A", "a")
        .add("B", "bb")
        .build()
    assertThat(headers.toString()).isEqualTo("A: a\nB: bb\n")
  }

  @Test fun headersToStringRedactsSensitiveHeaders() {
    val headers =
      Headers.Builder()
        .add("content-length", "99")
        .add("authorization", "peanutbutter")
        .add("proxy-authorization", "chocolate")

      CertificatePinner.Builder()
        .add("example.com", "sha1/" + certA1.certificate.sha1Hash().base64())
        .build()

    certificatePinner.check("example.com", listOf(certA1.certificate))
  }

  @Test fun successfulFindMatchingPins() {
    val certificatePinner =
      CertificatePinner.Builder()
        .add("first.com", certA1Sha256Pin, certB1Sha256Pin)
        .add("second.com", certC1Sha256Pin)
        .build()

        events.add(Message(string = text))
      }

      override fun onReadMessage(bytes: ByteString) {
        events.add(Message(bytes = bytes))
      }

      override fun onReadPing(payload: ByteString) {
        events.add(Ping(payload))
      }

      override fun onReadPong(payload: ByteString) {
        events.add(Pong(payload))
      }