}

  @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")

  private fun uppercase(original: BufferedSink): Sink =
    object : ForwardingSink(original) {
      override fun write(
        source: Buffer,
        byteCount: Long,
      ) {
        original.writeUtf8(source.readUtf8(byteCount).uppercase())
      }
    }

  private fun gzip(data: String): Buffer {
    val result = Buffer()
    val sink = GzipSink(result).buffer()
    sink.writeUtf8(data)
    sink.close()

    val response1 = call1.execute()
    val response2 = call2.execute()
    assertThat(response1.body.source().readUtf8(3)).isEqualTo("ABC")
    assertThat(response2.body.source().readUtf8(3)).isEqualTo("GHI")
    assertThat(response1.body.source().readUtf8(3)).isEqualTo("DEF")
    assertThat(response2.body.source().readUtf8(3)).isEqualTo("JKL")
    val c0e0 = server.takeRequest()
    assertThat(c0e0.connectionIndex).isEqualTo(0)

          InetAddress.getByAddress(fromSource.readByteArray(4L))
        }

        ADDRESS_TYPE_DOMAIN_NAME -> {
          val domainNameLength: Int = fromSource.readByte() and 0xff
          val domainName = fromSource.readUtf8(domainNameLength.toLong())
          // Resolve HOSTNAME_THAT_ONLY_THE_PROXY_KNOWS to localhost.
          when {
            domainName.equals(HOSTNAME_THAT_ONLY_THE_PROXY_KNOWS, ignoreCase = true) -> {

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)

    assertThat(source.readByte() and 0xff).isEqualTo(0xef)
    assertThat(source.readByte() and 0xff).isEqualTo(0xbb)
    assertThat(source.readByte() and 0xff).isEqualTo(0xbf)
    assertThat(source.readUtf8()).isEqualTo("hello")
  }

  @Test
  fun bytesEmpty() {
    val body = body("")
    assertThat(body.bytes().size).isEqualTo(0)
  }

  @Test
  fun bytesSeesBom() {

    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)

        for (i in 0 until utf8.size) {
          percentEncoded
            .writeUtf8("%")
            .writeUtf8(ByteString.of(utf8[i]).hex().uppercase())
        }
        return percentEncoded.readUtf8()
      }
    },

    /** URLs that contain this character in this component are invalid.  */
    FORBIDDEN,

    /** Hostnames that contain this character are encoded with punycode.  */
    PUNYCODE,

      if (includeBody && body != null) {
        val bodyBuffer = Buffer()
        body.writeTo(bodyBuffer)

        if (bodyBuffer.isProbablyUtf8()) {
          append(" \\\n  --data ${bodyBuffer.readUtf8().shellEscape()}")
        } else {
          append(" \\\n  --data-binary ${bodyBuffer.readByteString().hex().shellEscape()}")
        }
      }
    }

    index: Int,
  ) = cacheDir / "$key.$index.tmp"

  private fun readFile(file: Path): String =
    filesystem.read(file) {
      readUtf8()
    }

  private fun readFileOrNull(file: Path): String? =
    try {
      filesystem.read(file) {
        readUtf8()
      }
    } catch (_: FileNotFoundException) {
      null
    }

  fun writeFile(
    file: Path,