By default certificates use fast and secure 256-bit ECDSA keys. For interoperability with very old
clients use `HeldCertificate.Builder.rsa2048()`.

Download
--------

```kotlin
implementation("com.squareup.okhttp3:okhttp-tls:5.3.0")
```

 [held_certificate]: https://square.github.io/okhttp/4.x/okhttp-tls/okhttp3.tls/-held-certificate/

    builder = builder.signedBy(HeldCertificate.Builder().build())
    builder = builder.certificateAuthority(0)
    builder = builder.ecdsa256()
    builder = builder.rsa2048()
    val heldCertificate: HeldCertificate = builder.build()
  }

  @Test
  fun javaNetAuthenticator() {
    val authenticator = JavaNetAuthenticator()
    val response = Response.Builder().build()