Most applications should call `new OkHttpClient()` exactly once, configure it with their cache, and use that same instance everywhere. Otherwise the two cache instances will stomp on each other, corrupt the response cache, and possibly crash your program.

Response caching uses HTTP headers for all configuration. You can add request headers like `Cache-Control: max-stale=3600` and OkHttp's cache will honor them. Your webserver configures how long responses are cached with its own response...