* it can be used with collections that may contain null. This collection is a collection of
     * non-null elements, so we can treat it as a plain `Object[]`.
     */
    @SuppressWarnings("nullness")
    Object[] result = ObjectArrays.toArrayImpl(this);
    return result;
  }

  @Override

       *
       * (And I don't believe there's any situation in which we call x.combine(y) when x is a plain
       * ImmutableSet.Builder but y is an ImmutableSortedSet.Builder (or vice versa). Certainly
       * ImmutableSortedSet.Builder.combine() is written as if its argument will never be a plain
       * ImmutableSet.Builder: It casts immediately to ImmutableSortedSet.Builder.)
       */
      copyIfNecessary();

        .addHeader("Content-Type: text/plain")
        .addHeader("Last-Modified: " + formatDate(-2, TimeUnit.HOURS))
        .addHeader("Expires: " + formatDate(-1, TimeUnit.HOURS))
        .build(),
    )
    server.enqueue(
      MockResponse
        .Builder()
        .code(HttpURLConnection.HTTP_NOT_MODIFIED)
        .addHeader("Content-Type: text/plain")
        .addHeader("Content-Encoding: gzip")

### Deploy a more secure control plane with kubeadm

A new alpha feature allows running the kubeadm control plane components as non-root users. This is a long requested security measure in kubeadm. To try it you must enable the kubeadm-specific `RootlessControlPlane` feature gate. When you deploy a cluster using this alpha feature, your control plane runs with lower privileges.

    val call =
      client.newCall(
        Request(
          url = server.url("/foo"),
          body =
            object : RequestBody() {
              override fun contentType(): MediaType = "text/plain; charset=utf-8".toMediaType()

              override fun writeTo(sink: BufferedSink) {
                sink.write(postBytes)
              }
            },
        ),
      )

            });
        }

        @Override
        public OptionalThing<String> getSavedPlainText() {
            return OptionalThing.ofNullable(plainText, () -> {
                throw new IllegalStateException("Plain text not found");
            });
        }

        @Override
        public OptionalThing<String> getSavedHtmlText() {
            return OptionalThing.empty();
        }

        @Override

- Restores priority of static control plane pods in the cluster/gce/manifests control-plane manifests ([#89970](https://github.com/kubernetes/kubernetes/pull/89970), [@liggitt](https://github.com/liggitt)) [SIG Cluster Lifecycle and Node]


# v1.18.1

- github.com/bufbuild/protovalidate-go: [v0.9.1](https://github.com/bufbuild/protovalidate-go/tree/v0.9.1)
- github.com/envoyproxy/go-control-plane/envoy: [v1.32.4](https://github.com/envoyproxy/go-control-plane/tree/envoy/v1.32.4)
- github.com/envoyproxy/go-control-plane/ratelimit: [v0.1.0](https://github.com/envoyproxy/go-control-plane/tree/ratelimit/v0.1.0)
- github.com/go-jose/go-jose/v4: [v4.0.4](https://github.com/go-jose/go-jose/tree/v4.0.4)

     *
     * Unfortunately, we don't distinguish between these two cases in our public API: Joiner.on(...)
     * and Joiner.on(...).useForNull(...) both declare the same return type: plain Joiner. To ensure
     * that users *can* pass null arguments to Joiner, we annotate it as if it always tolerates null
     * inputs, rather than as if it never tolerates them.
     *

are hence enabled by default. This will be fixed in a future release.
[#38593](https://github.com/kubernetes/kubernetes/issues/38593)
* Federation control plane can be upgraded by updating the image
fields in the `Deployment` specs of the control plane components.
However, federation control plane upgrades were not tested in this
release [38537](https://github.com/kubernetes/kubernetes/issues/38537)

## Notable Changes to Existing Behavior