docs: static ConnectionSpec convertSpec(com.squareup.okhttp.ConnectionSpec spec) {
      Preconditions.checkArgument(spec.isTls(), "plaintext ConnectionSpec is not accepted");
  
      List<com.squareup.okhttp.TlsVersion> tlsVersionList = spec.tlsVersions();
      String[] tlsVersions = new String[tlsVersionList.size()];
      for (int i = 0; i < tlsVersions.length; i++) {
        tlsVersions[i] = tlsVersionList.get(i).javaName();
      }
  
      List<com.squareup.okhttp.CipherSuite> cipherSuiteList = spec.cipherSuites();
      CipherSuite[] cipherSuites = new CipherSuite[cipherSuiteList.size()];
      for (int i = 0; i < cipherSuites.length; i++) {
        cipherSuites[i] = CipherSuite.valueOf(cipherSuiteList.get(i).name());
      }
  
      return new ConnectionSpec.Builder(spec.isTls())
          .supportsTlsExtensions(spec.supportsTlsExtensions())
          .tlsVersions(tlsVersions)
          .cipherSuites(cipherSuites)
          .build();
    }