@Test fun ofMapAcceptsEmptyValue() {
    val headers = mapOf("User-Agent" to "").toHeaders()
    assertThat(headers.value(0)).isEqualTo("")
  }

  @Test fun ofMapTrimsKey() {
    val headers = mapOf(" User-Agent " to "OkHttp").toHeaders()
    assertThat(headers.name(0)).isEqualTo("User-Agent")
  }

  @Test fun ofMapTrimsValue() {
    val headers = mapOf("User-Agent" to " OkHttp ").toHeaders()

  val headers: List<String>? by option("-H", "--header", help = "Custom header to pass to server").multiple()

  val userAgent: String by option("-A", "--user-agent", help = "User-Agent to send to server").default(NAME + "/" + versionString())

  val connectTimeout: Int by option(
    "--connect-timeout",
    help = "Maximum time allowed for connection (seconds)",
  ).int().default(DEFAULT_TIMEOUT)

      .assertLogEqual("--> GET $url http/1.1")
      .assertLogEqual("Host: $host")
      .assertLogEqual("Connection: Keep-Alive")
      .assertLogEqual("Accept-Encoding: gzip")
      .assertLogMatch(Regex("""User-Agent: okhttp/.+"""))
      .assertLogEqual("--> END GET")
      .assertLogMatch(Regex("""<-- 200 OK $url \(\d+ms\)"""))
      .assertLogEqual("Content-Length: 0")
      .assertLogEqual("<-- END HTTP")
      .assertNoMoreLogs()

object OkHttp {
  /**
   * This is a string like "4.5.0-RC1", "4.5.0", or "4.6.0-SNAPSHOT" indicating the version of
   * OkHttp in the current runtime. Use this to include the OkHttp version in custom `User-Agent`
   * headers.
   *
   * Official OkHttp releases follow [semantic versioning][semver]. Versions with the `-SNAPSHOT`
   * qualifier are not unique and should only be used in development environments. If you create

    assertThat(recorded.headers["Accept-Encoding"]).isEqualTo("gzip, x-gzip, deflate")
    assertThat(recorded.headers["Connection"]).isEqualTo("keep-alive")
    assertThat(recorded.headers["User-Agent"]!!).startsWith("Apache-HttpClient/")
  }

    }
    assertThat(recorded.headers["HTTP2-Settings"]).isNotNull()
    assertThat(recorded.headers["Upgrade"]).isEqualTo("h2c") // HTTP/2 over plaintext!
    assertThat(recorded.headers["User-Agent"]!!).matches(Regex("Java-http-client/.*"))
  }

    assertFailsWith<NullPointerException> {
      (mapOf("User-Agent" to null) as Map<String, String>).toHeaders()
    }
  }

  @Test fun toMultimapGroupsHeaders() {
    val headers =
      Headers.headersOf(
        "cache-control",
        "no-cache",
        "cache-control",
        "no-store",
        "user-agent",
        "OkHttp",
      )
    val headerMap = headers.toMultimap()

OkHttpClient client = new OkHttpClient.Builder()
    .addInterceptor(new LoggingInterceptor())
    .build();

Request request = new Request.Builder()
    .url("http://www.publicobject.com/helloworld.txt")
    .header("User-Agent", "OkHttp Example")
    .build();

Response response = client.newCall(request).execute();
response.body().close();
```

        .url(server.url("/"))
        .head()
        .header("User-Agent", "SyncApiTest")
        .build()
    executeSynchronously(request)
      .assertCode(200)
      .assertHeader("Content-Type", "text/plain")
    val recordedRequest = server.takeRequest()
    assertThat(recordedRequest.method).isEqualTo("HEAD")
    assertThat(recordedRequest.headers["User-Agent"]).isEqualTo("SyncApiTest")

    val parts = header.split(':', limit = 2)
    if (!isSpecialHeader(parts[0])) {
      request.header(parts[0], parts[1])
    }
  }
  referer?.let {
    request.header("Referer", it)
  }
  request.header("User-Agent", userAgent)

  return request.build()
}

private fun Main.mediaType(): MediaType? {
  val mimeType =
    headers?.let {
      for (header in it) {
        val parts = header.split(':', limit = 2)