server.enqueue(
      MockResponse.Builder()
        .addHeader("Allow: GET, HEAD")
        .addHeader("Last-Modified: " + formatDate(-1, TimeUnit.HOURS))
        .addHeader("Cache-Control: max-age=0")
        .body("A")
        .build(),
    )
    server.enqueue(
      MockResponse.Builder()
        .addHeader("Allow: GET, HEAD, PUT")
        .code(HttpURLConnection.HTTP_NOT_MODIFIED)

- Added to `MutableFeatureGate` the ability to override the default setting of feature gates, to allow default-enabling a feature on a component-by-component basis instead of for all affected components simultaneously. ([#122647](https://github.com/kubernetes/kubernetes/pull/122647), [@benluddy](https://github.com/benluddy))