PluginExecution existing = merged.get(key);
                    if (existing != null) {
                        element = mergePluginExecution(existing, element, sourceDominant, context);
                    }
                    merged.put(key, element);
                }

                builder.executions(merged.values());
            }
        }

        @Override

    @Nullable
    Object getInputLocation();

    default XmlNode merge(@Nullable XmlNode source) {
        return merge(source, (Boolean) null);
    }

    XmlNode merge(@Nullable XmlNode source, @Nullable Boolean childMergeOverride);

    /**
     * Merge recessive into dominant and return either {@code dominant}
     * with merged information or a clone of {@code recessive} if
     * {@code dominant} is {@code null}.

                merged.put(key, element);
            }

            for (Repository element : recessive) {
                Object key = getRepositoryKey().apply(element);
                if (!merged.containsKey(key)) {
                    merged.put(key, element);
                }
            }

            builder.repositories(merged.values());
        }
    }

    @Override

        Settings recessive = Settings.newBuilder()
                .pluginGroups(Arrays.asList("org.codehaus.plexus"))
                .build();

        Settings merged = SettingsUtilsV4.merge(dominant, recessive);

        List<String> pluginGroups = merged.getPluginGroups();

        assertNotNull(pluginGroups);
        assertEquals(3, pluginGroups.size());
        assertEquals("org.apache.maven.plugins", pluginGroups.get(0));

                    PluginExecution existing = merged.get(key);
                    if (existing != null) {
                        element = mergePluginExecution(element, existing, sourceDominant, context);
                    }
                    merged.put(key, element);
                }

                builder.executions(merged.values());
            }
        }
    }

                    .build();
            model.update(merger.merge(model.getDelegate(), lifecycleModel));
        }
    }

    /**
     *  The domain-specific model merger for lifecycle bindings
     */
    protected static class LifecycleBindingsMerger extends MavenModelMerger {

        private static final String PLUGIN_MANAGEMENT = "plugin-management";

        public Model merge(Model target, Model source) {

        PomTestWrapper pom = buildPom("merged-plugin-exec-goals-order/wo-plugin-mgmt/sub");

        assertEquals(5, ((List<?>) pom.getValue("build/plugins[1]/executions[1]/goals")).size());
        assertEquals("child-a", pom.getValue("build/plugins[1]/executions[1]/goals[1]"));
        assertEquals("merged", pom.getValue("build/plugins[1]/executions[1]/goals[2]"));

    }

    @Deprecated
    public void merge(File existing, File result) throws RepositoryException {
        merge(existing != null ? existing.toPath() : null, result != null ? result.toPath() : null);
    }

    @Override
    public void merge(Path existing, Path result) throws RepositoryException {
        Metadata recessive = read(existing);

        merge(recessive);

        write(result, metadata);

                while (execs.putIfAbsent(id, e.withId(id)) != null) {
                    id = e.getId() + "-" + (++i);
                }
            });
            Plugin merged = cur.withExecutions(execs.values());
            plugins.put(merged, merged);
        }
    }

    private static String getExecutionId(Plugin plugin, String goal) {
        Set<String> existingIds = plugin != null

            Map<String, String> merged = new HashMap<>();
            if (sourceDominant) {
                merged.putAll(target.getProperties());
                putAll(merged, source.getProperties(), CHILD_DIRECTORY_PROPERTY);
            } else {
                putAll(merged, source.getProperties(), CHILD_DIRECTORY_PROPERTY);
                merged.putAll(target.getProperties());
            }