validator.validate(settings, problems);
        assertEquals(1, problems.messages.size());
        assertContains(
                problems.messages.get(0), "'servers.server.id' must be unique but found duplicate server with id test");
    }

    @Test
    void testValidateUniqueProfileId() throws Exception {
        Settings settings = new Settings();
        Profile profile1 = new Profile();

 *
 */
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}.

        }

        if (!included) {
            if (Objects.equals(winnerVersion, node.getArtifact().getVersion())) {
                details.add("omitted for duplicate");
            } else {
                details.add("omitted for conflict with " + winnerVersion);
            }
        }

        StringBuilder buffer = new StringBuilder();
        if (included) {

 files for the current project. if yes. then I'm able to find projects that
 can be offered to be opened together with the current project.
 problems with the current solution are:
 1. information is duplicate. once in POM's dependencies and once in the
 maven.multiproject.includes property.
 2. it works without problems only for projects with relative paths, e.g., from

         * the first occurrence. So when we're in lenient/compat mode, we have to deal with such broken POMs and mimic
         * the way 2.x works. When we're in strict mode, the removal of duplicates just saves other merging steps from
         * aftereffects and bogus error messages.
         */
        List<Dependency> dependencies = model.getDependencies();

                } else if (logger.isWarnEnabled()) {
                    Lifecycle original = phaseToLifecycleMap.get(phase);
                    logger.warn(
                            "Duplicated lifecycle phase {}. Defined in {} but also in {}",
                            phase,
                            original.getId(),
                            lifecycle.getId());
                }
            }

            lifecycle.phases().forEach(phase -> {
                if (!set.add(phase.name())) {
                    throw new IllegalArgumentException(
                            "Found duplicated phase '" + phase.name() + "' in '" + lifecycle.id() + "' lifecycle");
                }
            });
        }
    }

    @Override
    public Iterator<Lifecycle> iterator() {