client = new OkHttpClient.Builder()
        .connectionSpecs(Collections.singletonList(spec))
        .sslSocketFactory(customSslSocketFactory, trustManager)
        .build();
  }

  /**
   * Returns the VM's default SSL socket factory, using {@code trustManager} for trusted root
   * certificates.
   */
  private SSLSocketFactory defaultSslSocketFactory(X509TrustManager trustManager)

    sendRequest(client, "https://valid-isrgrootx1.letsencrypt.org/robots.txt");

    try {
      sendRequest(client, "https://google.com/robots.txt");
      if (androidMorEarlier) {
        // will pass with default CAs on N or later
        fail();
      }
    } catch (SSLHandshakeException sslhe) {
      assertTrue(androidMorEarlier);
    }
  }