assertThat(source.readUtf8()).isEqualTo("Hello")
      assertThat(response.trailers()).isEqualTo(headersOf("t1", "v2"))
    }

    val call2 = client.newCall(Request(server.url("/")))
    call2.execute().use { response ->
      val source = response.body.source()
      assertThat(response.header("h1")).isEqualTo("v1")
      assertThat(source.readUtf8()).isEqualTo("Hello")

     *
     * @param path
     *            The path. Must not be {@literal null} or empty.
     * @return The text read from the file.
     */
    public static String readUTF8(final String path) {
        assertArgumentNotEmpty("path", path);
        return readText(path, UTF8);
    }

    /**
     * Reads text from a file in UTF-8 encoding.
     *
     * @param file

          throw ProtocolException("Malformed close payload length of 1.")
        } else if (bufferSize != 0L) {
          code = controlFrameBuffer.readShort().toInt()
          reason = controlFrameBuffer.readUtf8()
          val codeExceptionMessage = WebSocketProtocol.closeCodeExceptionMessage(code)
          if (codeExceptionMessage != null) throw ProtocolException(codeExceptionMessage)
        }

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

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

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

    id: String?,
    type: String?,
    data: Buffer,
  ) {
    if (data.size != 0L) {
      lastId = id
      data.skip(1L) // Leading newline.
      callback.onEvent(id, type, data.readUtf8())
    }
  }

  companion object {
    private val options =
      Options.of(
        // 0
        "\r\n".encodeUtf8(),
        // 1
        "\r".encodeUtf8(),
        // 2

  }

  @Test
  fun setBodyAdjustsHeaders() {
    val response = MockResponse().setBody("ABC")
    assertThat(headersToList(response)).containsExactly("Content-Length: 3")
    assertThat(response.getBody()!!.readUtf8()).isEqualTo("ABC")
  }

  @Test
  fun mockResponseAddHeader() {
    val response =
      MockResponse()
        .clearHeaders()
        .addHeader("Cookie: s=square")

            try (CurlResponse response = ComponentUtil.getCurlHelper()
                    .post("/_configsync/file")
                    .param("path", dictFile.getPath())
                    .body(FileUtil.readUTF8(file))
                    .execute()) {
                final Map<String, Object> contentMap = response.getContent(OpenSearchCurl.jsonParser());

assertEquals("POST /v1/chat/send HTTP/1.1", request.getRequestLine());
assertEquals("application/json; charset=utf-8", request.getHeaders().get("Content-Type"));
assertEquals("{}", request.getBody().readUtf8());
```

### Kotlin
```kotlin
val request = server.takeRequest()
assertEquals("POST /v1/chat/send HTTP/1.1", request.requestLine)

    val response1 = client.newCall(request).execute()
    val in1 = response1.body.source()
    assertThat(in1.readUtf8("I love ".length.toLong())).isEqualTo("I love ")
    in1.skip("puppies but hate ".length.toLong())
    assertThat(in1.readUtf8("spiders".length.toLong())).isEqualTo("spiders")
    assertThat(in1.exhausted()).isTrue()
    in1.close()
    assertThat(cache.writeSuccessCount()).isEqualTo(1)

    val requestBodyBytes =
      Buffer()
        .apply {
          request.body?.writeTo(this)
        }

    val decompressedRequestBody =
      GzipSource(requestBodyBytes).use {
        it.buffer().readUtf8()
      }
    assertThat(decompressedRequestBody).isEqualTo("This is the original message")
  }

  @Test
  fun cannotGzipWithoutABody() {
    assertFailsWith<IllegalStateException> {
      Request