for (PluginExecution execution : plugin.getExecutions()) {
                            if (executionId.equals(execution.getId())) {
                                // NOTE: The PluginConfigurationExpander already merged the plugin-level config in
                                dom = (Xpp3Dom) execution.getConfiguration();
                                break;
                            }
                        }

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

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

                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

            }
            List<Server> servers = settings.getServers();
            for (int i = 0; i < servers.size(); i++) {
                Server server = servers.get(i);
                String serverField = "servers.server[" + i + "]";
                validateStringEmpty(problems, serverField + ".username", server.getUsername(), msgS);

                    .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) {

 *
 */
public interface ModelNormalizer {

    /**
     * Merges duplicate elements like multiple declarations of the same build plugin in the specified model.
     *
     * @param model The model whose duplicate elements should be merged, must not be {@code null}.
     * @param request The model building request that holds further settings, must not be {@code null}.

        assertEquals(basedir, new File(repo.getBasedir()));
    }

    @Test
    void testAuthenticationHandling() {
        Server server = new Server();
        server.setId("repository");
        server.setUsername("jason");
        server.setPassword("abc123");

        ArtifactRepository repository =
                repositorySystem.createArtifactRepository("repository", "http://foo", null, null, null);

        for (Server server : decrypted.getServers()) {
            AuthenticationBuilder authBuilder = new AuthenticationBuilder();
            authBuilder.addUsername(server.getUsername()).addPassword(server.getPassword());
            authBuilder.addPrivateKey(server.getPrivateKey(), server.getPassphrase());
            authSelector.add(server.getId(), authBuilder.build());

              <models>
                <model>src/main/mdo/settings.mdo</model>
              </models>
              <templates>
                <template>merger.vm</template>
                <template>transformer.vm</template>
                <template>reader-stax.vm</template>
                <template>writer-stax.vm</template>
              </templates>
              <params>

    }

    @Override
    public MavenExecutionRequest addServer(Server server) {
        Objects.requireNonNull(server, "server cannot be null");

        for (Server p : getServers()) {
            if (p.getId() != null && p.getId().equals(server.getId())) {
                return this;
            }
        }

        getServers().add(server);

        return this;
    }

    @Override