private final OkHttpClient client;

  public CustomTrust() {
    // This implementation just embeds the PEM files in Java strings; most applications will
    // instead read this from a resource file that gets bundled with the application.

    HandshakeCertificates certificates = new HandshakeCertificates.Builder()
        .addTrustedCertificate(letsEncryptCertificateAuthority)

Sometimes there's an action required like calling the application layer or responding to a ping, and the thread discovering the action is not the thread that should do the work. We enqueue a runnable on this executor and it gets handled by one of the executor's threads.

### Locks

We have 3 different things that we synchronize on.

#### Http2Connection

# Calls

The HTTP client’s job is to accept your request and produce its response. This is simple in theory but it gets tricky in practice.

## [Requests](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-request/)

Each HTTP request contains a URL, a method (like `GET` or `POST`), and a list of headers. Requests may also contain a body: a data stream of a specific content type.

## [Responses](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-response/)

  private val client: OkHttpClient

  init {
    // This implementation just embeds the PEM files in Java strings; most applications will
    // instead read this from a resource file that gets bundled with the application.
    val certificates =
      HandshakeCertificates.Builder()
        .addTrustedCertificate(letsEncryptCertificateAuthority)
        .addTrustedCertificate(entrustRootCertificateAuthority)