val body = "\u0800".toRequestBody(contentType)
    assertThat(body.contentType()).isEqualTo("text/plain; charset=utf-8".toMediaType())
    assertThat(body.contentLength()).isEqualTo(3)
    assertThat(bodyToHex(body)).isEqualTo("e0a080")
  }

  @Test
  fun stringWithNonDefaultCharsetSpecified() {
    val contentType = "text/plain; charset=utf-16be".toMediaType()
    val body = "\u0800".toRequestBody(contentType)

      perMessageDeflate = true,
      noContextTakeover = false,
    )

  @AfterEach fun tearDown() {
    callback.assertExhausted()
  }

  @Test fun controlFramesMustBeFinal() {
    data.write("0a00".decodeHex()) // Empty pong.
    assertFailsWith<ProtocolException> {
      clientReader.processNextFrame()
    }.also { expected ->
      assertThat(expected.message)
        .isEqualTo("Control frames must be final.")