Object key = getPluginKey().apply(element);
                    Plugin existing = master.get(key);
                    if (existing != null) {
                        existing = mergePlugin(existing, element, sourceDominant, context);
                        master.put(key, existing);
                        if (!pending.isEmpty()) {
                            predecessors.put(key, pending);

### New properties in an existing class

When adding a property to an existing class (task, extension, domain object, etc), the API should consist of managed lazy properties.  However, some exceptions need to be made to keep backwards compatibility with existing builds.

This is preferred when the implementation type is internal:

```groovy

		expectedSync: false,
	},
	{ // 2. existing object replication config enabled, no versioning
		name:         "existing object replication config enabled, no versioning",
		info:         ObjectInfo{Size: 100},
		rcfg:         replicationConfig{Config: &configs[0]},
		expectedSync: false,
	},
	{ // 3. existing object replication config enabled, versioning suspended

                for (Plugin element : tgt) {
                    Object key = getPluginKey().apply(element);
                    Plugin existing = master.get(key);
                    if (existing != null) {
                        element = mergePlugin(element, existing, sourceDominant, context);

                        master.put(key, element);

                        if (!pending.isEmpty()) {

### Existing object replication

			chainedCNIPlugin: true,
		},
		{
			name:              "specified existing CNI config file",
			chainedCNIPlugin:  true,
			specifiedConfName: "list.conflist",
			expectedConfName:  "list.conflist",
			existingConfFiles: []string{"bridge.conf", "list.conflist"},
		},
		{
			name:              "specified existing CNI config file (.conf to .conflist)",
			chainedCNIPlugin:  true,

	--remote-bucket http://minio:minio123@127.0.0.1:9004/bucket \
	--replicate "existing-objects,delete,delete-marker,replica-metadata-sync"
sleep 1

echo "adding replication rule for b -> a : ${remote_arn}"
./mc replicate add siteb/bucket/ \
	--remote-bucket http://minio:minio123@127.0.0.1:9001/bucket \
	--replicate "existing-objects,delete,delete-marker,replica-metadata-sync"
sleep 1

```

### Existing object replication

Existing object replication as detailed [here](https://aws.amazon.com/blogs/storage/replicating-existing-objects-between-s3-buckets/) can be enabled by passing `existing-objects` as a value to `--replicate` flag while adding or editing a replication rule.

    // next map.get()
    when(backingMap.get(KEY)).thenReturn(existingZero);
    // since get returned zero, try a replace; that fails due to a simulated race
    when(backingMap.replace(eq(KEY), eq(existingZero), isA(AtomicInteger.class))).thenReturn(false);
    when(backingMap.putIfAbsent(eq(KEY), isA(AtomicInteger.class))).thenReturn(existing);

    // another map.get()

			internalLogIf(ctx, err, logger.WarningKind)
			return true
		}
		if ret.RetainUntilDate.After(t) {
			return true
		}
	}
	return false
}

// enforceRetentionBypassForDelete enforces whether an existing object under governance can be deleted
// with governance bypass headers set in the request.
// Objects under site wide WORM can never be overwritten.