"Constructor com.example.Source(java.util.List): Parameter 0 from null accepting to non-null accepting breaking change."
            )
            assertHasNoWarning()
            assertHasNoInformation()
        }
    }

    @Test
    fun `from null array returning to non-null returning is not breaking`() {

            Element build = root.child("build").orElse(null);
            Element plugins = build.child("plugins").orElse(null);
            Element cleanPlugin = plugins.child("plugin").orElse(null);
            Element executions = cleanPlugin.child("executions").orElse(null);
            Element execution = executions.child("execution").orElse(null);
            Element phase = execution.child("phase").orElse(null);

        if (spec == null) {
            return null;
        }

        VersionRange cached = CACHE_SPEC.get(spec);
        if (cached != null) {
            return cached;
        }

        List<Restriction> restrictions = new ArrayList<>();
        String process = spec;
        ArtifactVersion version = null;
        ArtifactVersion upperBound = null;
        ArtifactVersion lowerBound = null;

        requireNonNull(event, "event cannot be null");

        if (!isLocalRepositoryArtifactOrMissing(event.getSession(), event.getArtifact())) {
            return;
        }

        RequestTrace trace = event.getTrace();

        CollectStepData collectStepTrace = null;
        ArtifactRequest artifactRequest = null;
        ArtifactDescriptorRequest artifactDescriptorRequest = null;
        Plugin plugin = null;

        if (settings.isUsePluginRegistry()) {
            addViolation(problems, Severity.WARNING, "usePluginRegistry", null, "is deprecated and has no effect.");
        }

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

        if (pluginGroups != null) {
            for (int i = 0; i < pluginGroups.size(); i++) {
                String pluginGroup = pluginGroups.get(i).trim();

                    e);

            return null;
        }

        return artifactFactory.createPluginArtifact(plugin.getGroupId(), plugin.getArtifactId(), versionRange);
    }

    public ArtifactRepositoryPolicy buildArtifactRepositoryPolicy(RepositoryPolicy policy) {
        boolean enabled = true;

        String updatePolicy = null;

        String checksumPolicy = null;

        if (policy != null) {

                        lineNumber, columnNumber, source != null ? source.toApiSource() : null);
            }
        } else {
            return org.apache.maven.api.model.InputLocation.of(
                    lineNumber,
                    columnNumber,
                    source != null ? source.toApiSource() : null,
                    locations != null

        this.syncContextFactory = Objects.requireNonNull(syncContextFactory, "syncContextFactory cannot be null");
        this.repositoryEventDispatcher =
                Objects.requireNonNull(repositoryEventDispatcher, "repositoryEventDispatcher cannot be null");
        this.versionScheme = Objects.requireNonNull(versionScheme, "versionScheme cannot be null");
    }

    @Override

    }

    private String join(String message1, String message2) {
        String message = "";

        if (message1 != null && !message1.isEmpty()) {
            message = message1.trim();
        }

        if (message2 != null && !message2.isEmpty()) {
            if (message != null && !message.isEmpty()) {
                if (message.endsWith(".") || message.endsWith("!") || message.endsWith(":")) {

        // Check build/plugins
        Element buildElement = root.child(BUILD).orElse(null);
        if (buildElement != null) {
            Element pluginsElement = buildElement.child(PLUGINS).orElse(null);
            if (pluginsElement != null) {
                hasUpgrades |= upgradePluginsInSection(