.build()
    val server = MockWebServer()
    server.useHttps(handshakeCertificates.sslSocketFactory(), false)
    ```

    Get these strings with `HeldCertificate.certificatePem()` and `privateKeyPkcs8Pem()`.

 *  Fix: Handshake now returns peer certificates in canonical order: each certificate is signed by
    the certificate that follows and the last certificate is signed by a trusted root.