*
 * ## Warning: Certificate Pinning is Dangerous!
 *
 * Pinning certificates limits your server team's abilities to update their TLS certificates. By
 * pinning certificates, you take on additional operational complexity and limit your ability to
 * migrate between certificate authorities. Do not use certificate pinning without the blessing of
 * your server's TLS administrator!
 *

    // rogue CA is trusted) but it should fail certificate pinning.
    val request =
      Request
        .Builder()
        .url(server.url("/"))
        .build()
    val call = client.newCall(request)
    assertFailsWith<SSLPeerUnverifiedException> {
      call.execute()
    }.also { expected ->
      // Certificate pinning fails!

Use [CertificatePinner](https://square.github.io/okhttp/5.x/okhttp/okhttp3/-certificate-pinner/) to restrict which certificates and certificate authorities are trusted. Certificate pinning increases security, but limits your server team’s abilities to update their TLS certificates. **Do not use certificate pinning without the blessing of your server’s TLS administrator!**

=== ":material-language-kotlin: Kotlin"
    ```kotlin
      private val client = OkHttpClient.Builder()

first connect fails. This is necessary for IPv4+IPv6 and services hosted in redundant data
centers. OkHttp supports modern TLS features (TLS 1.3, ALPN, certificate pinning). It can be
configured to fall back for broad connectivity.

Using OkHttp is easy. Its request/response API is designed with fluent builders and immutability. It

      // do not retry.
      if (e.cause is CertificateException) {
        return false
      }
    }
    if (e is SSLPeerUnverifiedException) {
      // e.g. a certificate pinning error.
      return false
    }
    // An example of one we might want to retry with a different route is a problem connecting to a

   * Sec-Token-Binding}</a> header field name.
   *
   * @since 25.1
   */
  public static final String SEC_TOKEN_BINDING = "Sec-Token-Binding";

  /**
   * The HTTP <a href="https://datatracker.ietf.org/doc/html/draft-ietf-tokbind-ttrp">{@code
   * Sec-Provided-Token-Binding-ID}</a> header field name.
   *
   * @since 25.1
   */

    TF_Status status;
    // Let this custom device choose the device to pin this op on if it
    // implements the pinning function.
    if (device_.shall_pin_to_this_device != nullptr) {
      return device_.shall_pin_to_this_device(tensorflow::wrap(op), &status);
    }
    return errors::Unimplemented("No custom device pinning implementation.");
  }

 private:
  TFE_Context* context_;
  TFE_CustomDevice device_;
  void* info_;

    // Fails on 11.0.1 https://github.com/square/okhttp/issues/4703
    enableTls()
    server.enqueue(MockResponse())
    server.enqueue(MockResponse())

    // Make a first request without certificate pinning. Use it to collect certificates to pin.
    val request1 = Request.Builder().url(server.url("/")).build()
    val response1 = client.newCall(request1).execute()
    val certificatePinnerBuilder = CertificatePinner.Builder()

    /**
     * Sets the certificate pinner that constrains which certificates are trusted. By default HTTPS
     * connections rely on only the [SSL socket factory][sslSocketFactory] to establish trust.
     * Pinning certificates avoids the need to trust certificate authorities.
     */
    fun certificatePinner(certificatePinner: CertificatePinner) =
      apply {
        if (certificatePinner != this.certificatePinner) {

* Add docs for: [Testing **FastAPI**](https://fastapi.tiangolo.com/tutorial/testing/). PR [#151](https://github.com/tiangolo/fastapi/pull/151).

* Update `/docs` Swagger UI to enable deep linking. This allows sharing the URL pointing directly to the *path operation* documentation in the docs. PR [#148](https://github.com/tiangolo/fastapi/pull/148) by [@wshayes](https://github.com/wshayes).