Object value = null;

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

        String expression = stripTokens(expr);
        if (expression.equals(expr)) {
            int index = expr.indexOf("${");
            if (index >= 0) {
                int lastIndex = expr.indexOf('}', index);
                if (lastIndex >= 0) {

     * Module information for the path specified at construction time.
     * This map is usually either empty if no module was found, or a singleton map.
     * It may however contain more than one entry if module hierarchy was detected,
     * in which case there is one key per sub-directory.
     *
     * <p>This map may contain null values if the constructor was invoked with {@code resolve}

            // There is no need to check if the build has created any outputs, see MNG-2222.
            boolean projectCompiledDuringThisSession =
                    project.hasLifecyclePhase("compile") && COMPILE_PHASE_TYPES.contains(type);

            // Check if the project is part of the session (not filtered by -pl, -rf, etc). If so, we check

        while (trace != null) {
            Object data = trace.getData();
            if (data instanceof CollectStepData) {
                collectStepTrace = (CollectStepData) data;
            } else if (data instanceof ArtifactDescriptorRequest) {
                artifactDescriptorRequest = (ArtifactDescriptorRequest) data;
            } else if (data instanceof ArtifactRequest) {
                artifactRequest = (ArtifactRequest) data;

        String updatePolicy = null;

        String checksumPolicy = null;

        if (policy != null) {
            enabled = policy.isEnabled();

            if (policy.getUpdatePolicy() != null) {
                updatePolicy = policy.getUpdatePolicy();
            }
            if (policy.getChecksumPolicy() != null) {
                checksumPolicy = policy.getChecksumPolicy();
            }

                PluginValidationIssues issues = entry.getValue();
                if (!hasAnythingToReport(issues, issueLocalitiesToReport)) {
                    continue;
                }
                logger.warn(" * {}", entry.getKey());
                if (validationReportLevel == ValidationReportLevel.VERBOSE) {
                    if (!issues.pluginDeclarations.isEmpty()) {

            boolean isBlankVersion = descriptor.getRequiredMavenVersion() == null
                    || descriptor.getRequiredMavenVersion().trim().isEmpty();

            if (isBlankVersion) {
                // only take value from underlying POM if plugin descriptor has no explicit Maven requirement
                descriptor.setRequiredMavenVersion(artifact.getProperty("requiredMavenVersion", null));
            }

        public boolean isStale() {
            File pomFile = pomArtifact.getFile();
            if (pomFile != null) {
                if (pomFile.canRead()) {
                    return length != pomFile.length() || timestamp != pomFile.lastModified();
                } else {
                    // if the POM didn't exist, retry if any repo is configured to always update
                    boolean snapshot = pomArtifact.isSnapshot();

        Collection<String> scopes = Collections.emptyList();

        if (classpath != null && !classpath.isEmpty()) {
            if (Artifact.SCOPE_COMPILE.equals(classpath)) {
                scopes = Arrays.asList(Artifact.SCOPE_COMPILE, Artifact.SCOPE_SYSTEM, Artifact.SCOPE_PROVIDED);
            } else if (Artifact.SCOPE_RUNTIME.equals(classpath)) {

        }
        RecursionInterceptor recursionInterceptor = createRecursionInterceptor(request);
        return value -> {
            if (value != null && value.contains("${")) {
                String c = cache.get(value);
                if (c == null) {
                    try {
                        c = interpolator.interpolate(value, recursionInterceptor);