Date:   Wed Nov 17 15:49:12 2021 -0800

    heal legacy objects when versioning is enabled after upgrade (#13671)
```

- A security fix must be backported if a customer is affected by it, we have a mechanism in SUBNET to send out notifications to affected customers in such situations, this is a mandatory requirement.

```
commit 99bf4d0c429f04dbd013ba98840d07b759ae1702 (tag: RELEASE.2019-06-15T23-07-18Z)
Author: Harshavardhana <******@****.***>

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;

/**
 * A semi-persistent mapping from keys to values. Values are automatically loaded by the cache, and
 * are stored in the cache until either evicted or manually invalidated. The common way to build
 * instances is using {@link CacheBuilder}.
 *

    /**
     * <p>Streams an object to the client application.
     *
     * <p>The client application can receive objects sent using this method by registering a {@link StreamedValueListener}.
     * The client application receives objects in the order they were sent, and before it receives the result of the {@link BuildAction}.</p>
     *

You can also use the <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PATCH" class="external-link" target="_blank">HTTP `PATCH`</a> operation to *partially* update data.

This means that you can send only the data that you want to update, leaving the rest intact.

!!! note
    `PATCH` is less commonly used and known than `PUT`.

    And many teams use only `PUT`, even for partial updates.

    /**
     * @return true if the <b>debug</b> error level is enabled
     */
    boolean isDebugEnabled();

    /**
     * Send a message to the user in the <b>debug</b> error level.
     *
     * @param content
     */
    void debug(CharSequence content);

    /**
     * Send a message (and accompanying exception) to the user in the <b>debug</b> error level.<br>

proxy1     cluster1     STALE        SYNCED      SYNCED      NOT SENT     SYNCED       istiod1     1.20
proxy2     cluster2     STALE        SYNCED      STALE       SYNCED       STALE        istiod2     1.19
proxy3     cluster3     NOT SENT     ERROR       STALE       NOT SENT     NOT SENT     istiod3     1.20

        dep -->> handler: Auto forward exception
    end
    operation ->> client: Return response to client
    Note over client,operation: Response is already sent, can't change it anymore
    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> dep: Raise other exception
    end
    Note over dep: After yield
    opt Handle other exception

NAME       CLUSTER      CDS       LDS        EDS        RDS          ECDS         ISTIOD      VERSION
proxy1     cluster1     STALE     SYNCED     SYNCED     NOT SENT     NOT SENT     istiod1     1.20

func _[T any](ch T) {
	ch <- /* ERRORx `cannot send to ch .* no core type` */ 0
}

func _[T C0](ch T) {
	ch <- /* ERROR "cannot send to non-channel" */ 0
}

func _[T C1](ch T) {
	ch <- 0
}

func _[T C2](ch T) {
	ch  <-/* ERROR "cannot send to receive-only channel" */ 0
}

func _[T C3](ch T) {
	ch <- /* ERRORx `cannot send to ch .* no core type` */ 0
}

func _[T C4](ch T) {
	ch <- 0

			}
			u := evalOrig(v.ID, ancestor, semi, label)
			if semi[u] < semi[w] {
				semi[w] = semi[u]
			}
		}

		// add w to bucket[vertex[semi[w]]]
		// implement bucket as a linked list implemented
		// in a pair of arrays.
		vsw := vertex[semi[w]]
		bucketLink[w] = bucketHead[vsw]
		bucketHead[vsw] = w

		linkOrig(parent[w], w, ancestor)

		// step3 in TOPLAS paper