clientReader.processNextFrame()
    }.also { expected ->
      assertThat(expected.message).isEqualTo("Unexpected rsv2 flag")
    }
    data.clear()
    data.write("9a00".decodeHex()) // Empty pong, flag 3 set.
    assertFailsWith<ProtocolException> {
      clientReader.processNextFrame()
    }.also { expected ->
      assertThat(expected.message).isEqualTo("Unexpected rsv3 flag")
    }
  }

  @Test
  fun onePartRequired() {
    assertFailsWith<IllegalStateException> {
      MultipartBody.Builder().build()
    }.also { expected ->
      assertThat(expected.message)
        .isEqualTo("Multipart body must have at least one part.")
    }
  }

  @Test
  fun singlePart() {
    val expected =
      """
      |--123
      |
      |Hello, World!
      |--123--
      |

    assertThat(buffer.readUtf8()).isEqualTo(expected)
  }

  @Test
  fun buildEmptyForm() {
    val body = FormBody.Builder().build()
    val expected = ""
    assertThat(body.contentLength()).isEqualTo(expected.length.toLong())
    val buffer = Buffer()
    body.writeTo(buffer)
    assertThat(buffer.readUtf8()).isEqualTo(expected)
  }

  @Test
  fun characterEncoding() {
    // Browsers convert '\u0000' to '%EF%BF%BD'.

        .build()
    val call = client.newCall(request)
    call.timeout().timeout(250, TimeUnit.MILLISECONDS)
    assertFailsWith<IOException> {
      call.execute()
    }.also { expected ->
      assertThat(expected.message).isEqualTo("timeout")
      assertThat(call.isCanceled()).isTrue()
    }
  }

  @Test
  fun timeoutWritingRequestWithEnqueue() {
    server.enqueue(MockResponse())
    val request =

        .add("Test-Instant", expected)
        .build()
    assertThat(headers["Test-Instant"]).isEqualTo("Thu, 01 Jan 1970 00:00:00 GMT")
    assertThat(headers.getInstant("Test-Instant")).isEqualTo(expected)
  }

  @Test fun setDate() {
    val expected = Date(1000)
    val headers =
      Headers.Builder()
        .add("testDate", Date(0L))
        .set("testDate", expected)
        .build()

  private val results = LinkedBlockingQueue<FutureTask<Void>>()

  fun receiveRequest(expected: String) =
    apply {
      actions += { stream ->
        val actual = stream.requestBody.readUtf8(expected.utf8Size())
        if (actual != expected) throw AssertionError("$actual != $expected")
      }
    }

  fun exhaustRequest() =
    apply {
      actions += { stream ->

        .header("Host", "square.com")
        .header("TE", "gzip")
        .build()
    val expected =
      headerEntries(
        ":method",
        "GET",
        ":path",
        "/",
        ":authority",
        "square.com",
        ":scheme",
        "http",
      )
    assertThat(http2HeadersList(request)).isEqualTo(expected)
  }

  @Test fun http2HeadersListDontDropTeIfTrailersHttp2() {
    val request =

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

  @Test
  fun networkInterceptorsCannotCallProceedMultipleTimes() {

        arrayOf(serverCertificate.certificate, serverIntermediate.certificate),
        null,
      )

    assertFailsWith<IOException> {
      sslSession.handshake()
    }.also { expected ->
      assertThat(expected).hasMessage("cipherSuite == SSL_NULL_WITH_NULL_NULL")
    }
  }

  @Test
  fun tlsWithNullNullNull() {
    val sslSession =
      FakeSSLSession(
        "TLSv1.3",

    assertFailsWith<IOException> {
      client.newCall(request).execute()
    }.also { expected ->
      expected.assertSuppressed {
        val suppressed = it.single()
        assertThat(suppressed).isInstanceOf(IOException::class.java)
        assertThat(suppressed).isNotSameAs(expected)
      }
    }
  }

  /** Confirm suppressed exceptions that occur after connecting are returned. */