Set<Binding<Object>> res3 = res2 != null ? new HashSet<>(res2) : new HashSet<>();
                        Map<String, Supplier<Object>> map = res3.stream()
                                .filter(b -> b.getOriginalKey() == null
                                        || b.getOriginalKey().getQualifier() == null
                                        || b.getOriginalKey().getQualifier() instanceof String)

         * expression from properties only.
         */
        if (value != null && type != null && !(value instanceof String) && !isTypeCompatible(type, value)) {
            value = null;
        }

        if (value == null) {
            // The CLI should win for defining properties

            if (properties != null) {
                // We will attempt to get nab a property as a way to specify a parameter

            if (delegate.getRange() == null) {
                return null;
            }
            return new DefaultVersionRange(versionScheme, delegate.getRange());
        }

        @Override
        public Version getRecommendedVersion() {
            if (delegate.getVersion() == null) {
                return null;
            }

                .session(nonNull(session, "session cannot be null"))
                .globalToolchainsSource(
                        globalToolchainsPath != null && Files.exists(globalToolchainsPath)
                                ? Source.fromPath(globalToolchainsPath)
                                : null)
                .userToolchainsSource(
                        userToolchainsPath != null && Files.exists(userToolchainsPath)

     *
     * @param groupId the group identifier, or {@code null} is unspecified
     * @param artifactId the artifact identifier, or {@code null} is unspecified
     * @param version the artifact version, or {@code null} is unspecified
     * @param classifier the artifact classifier, or {@code null} is unspecified
     * @param extension the artifact extension, or {@code null} is unspecified

            if (expression == null || expression.trim().isEmpty()) {
                return null;
            }

            try {
                return ReflectionValueExtractor.evaluate(expression, root, false);
            } catch (Exception e) {
                addFeedback("Failed to extract \'" + expression + "\' from: " + root, e);
            }

            return null;
        }
    }

    /**

        if (a.getVersion() != null) {
            result = 31 * result + a.getVersion().hashCode();
        }
        result = 31 * result + (a.getClassifier() != null ? a.getClassifier().hashCode() : 0);
        result = 31 * result + (a.getScope() != null ? a.getScope().hashCode() : 0);
        result = 31 * result
                + (a.getDependencyFilter() != null ? a.getDependencyFilter().hashCode() : 0);

                if (!acquiredAggregatorLock.tryLock()) {
                    Thread owner = aggregatorLock.getOwner();
                    MojoDescriptor ownerMojo = owner != null ? mojos.get(owner) : null;
                    String str = ownerMojo != null ? " The " + ownerMojo.getId() : "An";
                    String msg = str + " aggregator mojo is already being executed "

        }
        CollectRequest collectRequest = new CollectRequest()
                .setRootArtifact(rootArtifact != null ? session.toArtifact(rootArtifact) : null)
                .setRoot(root != null ? session.toDependency(root, false) : null)
                .setDependencies(session.toDependencies(dependencies, false))
                .setManagedDependencies(session.toDependencies(managedDependencies, true))

    @BeforeEach
    void setUp() throws Exception {
        policy = new DefaultGraphConflictResolutionPolicy();
        e1 = new MetadataGraphEdge("1.1", true, null, null, 2, 1);
        e2 = new MetadataGraphEdge("1.2", true, null, null, 3, 2);
        e3 = new MetadataGraphEdge("1.2", true, null, null, 2, 3);
    }

    // ------------------------------------------------------------------------------------------
    @Test