builder.socketFactory(SSLSocketFactory.getDefault())
    }
  }

  @Test fun noSslSocketFactoryConfigured() {
    val client =
      OkHttpClient
        .Builder()
        .connectionSpecs(listOf(ConnectionSpec.CLEARTEXT))
        .build()
    assertFailsWith<IllegalStateException> {
      client.sslSocketFactory
    }
  }

  @Test fun nullHostileProtocolList() {
    val nullHostileProtocols =

        .hostnameVerifier(RecordingHostnameVerifier())
        .connectionSpecs(
          // Attempt RESTRICTED_TLS then fall back to MODERN_TLS.
          listOf(
            ConnectionSpec.RESTRICTED_TLS,
            ConnectionSpec.MODERN_TLS,
          ),
        ).sslSocketFactory(
          suppressTlsFallbackClientSocketFactory(),
          handshakeCertificates.trustManager,
        ).build()

      OverrideParam.RetryOnConnectionFailure -> {
        enableTls()
        var first = true
        client =
          client
            .newBuilder()
            .connectionSpecs(listOf(ConnectionSpec.RESTRICTED_TLS, ConnectionSpec.MODERN_TLS))
            .eventListener(
              object : EventListener() {
                override fun secureConnectEnd(
                  call: Call,
                  handshake: Handshake?,

        .newBuilder()
        .hostnameVerifier(
          RecordingHostnameVerifier(),
        ) // Attempt RESTRICTED_TLS then fall back to MODERN_TLS.
        .connectionSpecs(Arrays.asList(ConnectionSpec.RESTRICTED_TLS, ConnectionSpec.MODERN_TLS))
        .sslSocketFactory(
          suppressTlsFallbackClientSocketFactory(),
          handshakeCertificates.trustManager,
        ).build()

    configure OkHttp 3.13 to allow TLSv1 and TLSv1.1 connections:

    ```
    OkHttpClient client = new OkHttpClient.Builder()
        .connectionSpecs(Arrays.asList(ConnectionSpec.COMPATIBLE_TLS))
        .build();
    ```

 *  New: You can now access HTTP trailers with `Response.trailers()`. This method may only be called
    after the entire HTTP response body has been read.