*  New: `okhttp-sse` is an early preview of Server-Sent Events (SSE). This feature is incomplete
    and is only suitable for experimental use.
 *  New: MockWebServer now supports client authentication (mutual TLS). Call `requestClientAuth()`
    to permit an optional client certificate or `requireClientAuth()` to require one.
 *  New: `RecordedRequest.getHandshake()` returns the HTTPS handshake of a request sent to
    `MockWebServer`.