Ideally, prioritized leader election gets upstreamed in the near future ([KEP](https://github.com/kubernetes/enhancements/pull/2836)), and hopefully what gets merged isn't too far from what we have forked here (if it is, we'd have to potentially maintain migration code in our fork for a few releases before abandoning). Once merged we can abandon this forked code and use upstream again....

		config.DefaultConfig.ProxyMetadata = map[string]string{
			"merged":  "original",
			"default": "foo",
		}
		mc, err := mesh.ApplyProxyConfig(`proxyMetadata: {"merged":"override","override":"bar"}`, config)
		assert.NoError(t, err)
		// Ensure we didn't modify the passed in mesh config
		assert.Equal(t, mc.DefaultConfig.ProxyMetadata, map[string]string{
			"merged":   "override",
			"default":  "foo",
			"override": "bar",

				vs := copiedDelegate.(*networking.VirtualService)
				merged := mergeHTTPRoutes(route, vs.Http)
				mergedRoutes = append(mergedRoutes, merged...)
			} else {
				mergedRoutes = append(mergedRoutes, route)
			}
		}
		rootVs.Http = mergedRoutes
		if log.DebugEnabled() {
			vsString, _ := protomarshal.ToJSONWithIndent(rootVs, "   ")
			log.Debugf("merged virtualService: %s", vsString)
		}
		out = append(out, root)

    /**
     * Returns a new manifest instance where all the attribute values are expanded (e.g. their toString method is called).
     * The returned manifest also contains all the attributes of the to be merged manifests specified in {@link #from(Object...)}.
     */
    Manifest getEffectiveManifest();

    /**

			return nil
		}
		merged.Ref = m2.Ref
	}

	switch {
	case merged == *m1:
		return m1
	case merged == *m2:
		return m2
	default:
		// Clone the result to avoid an alloc for merged
		// if the result is equal to one of the arguments.
		clone := merged
		return &clone
	}
}

// addVersions fills in m.Versions with the list of known versions.

  Operation* first_op_after = islands.back()->getNextNode();

  // We create the merged island at the location of the first island that was
  // merged (excluding special TPU input/output ops).
  IslandOp new_island = CreateMergedIsland(island, islands, wrapped_ops);

  // Ensure dominance by sorting the range of islands that were merged.
  return SortTopologically(Block::iterator(new_island.getOperation()),

    /**
     * Merges the specified source object into the given target object.
     *
     * @param target The target object whose existing contents should be merged with the source, must not be
     *            <code>null</code>.
     * @param source The (read-only) source object that should be merged into the target object, may be
     *            <code>null</code>.

                    if (dependency != null) {
                        Dependency merged = mergeDependency(dependency, managedDependency, false, context);
                        if (merged != dependency) {
                            dependencies.put(key, merged);
                            modified = true;
                        }
                    }
                }

     * @see #SELF_COMBINATION_MODE_ATTRIBUTE
     * @param dominant The dominant DOM into which the recessive value/attributes/children will be merged
     * @param recessive The recessive DOM, which will be merged into the dominant DOM
     * @return merged DOM
     */
    public static XmlNode merge(XmlNode dominant, XmlNode recessive) {
        return merge(dominant, recessive, null);
    }

    public Optional<MetadataSnapshot> getSnapshot() {
        return Optional.empty();
    }

    @Override
    protected FileSystemNode withIncompleteChildren(ChildMap<? extends FileSystemNode> merged) {
        return new UnknownFileSystemNode(merged);
    }

    @Override
    protected Optional<FileSystemNode> withAllChildrenRemoved() {
        return Optional.empty();
    }

    @Override