public void setSession(MavenSession session) {
        AtomicReference<MavenSession> reference = DefaultLegacySupport.SESSION.get();
        if (reference != null) {
            reference.set(null);
        }

        if (session == null && reference != null) {
            DefaultLegacySupport.SESSION.remove();
        } else {
            DefaultLegacySupport.SESSION.set(new AtomicReference<>(session));
        }
    }

                        isAny(relocation.target.getGroupId()) ? null : relocation.target.getGroupId(),
                        isAny(relocation.target.getArtifactId()) ? null : relocation.target.getArtifactId(),
                        isAny(relocation.target.getClassifier()) ? null : relocation.target.getClassifier(),
                        isAny(relocation.target.getExtension()) ? null : relocation.target.getExtension(),

     * from the runtime environment like {@link System#getProperties()} and environment variables.
     *
     * @param systemProperties The system properties, may be {@code null}.
     * @return This request, never {@code null}.
     */
    ProjectBuildingRequest setSystemProperties(Properties systemProperties);

    /**

        PluginDescriptor pluginDescriptor = new PluginDescriptor();
        MojoDescriptor mojoDescriptor = new MojoDescriptor();
        mojoDescriptor.setPluginDescriptor(pluginDescriptor);
        MojoExecution mojoExecution = new MojoExecution(mojoDescriptor);
        Throwable exception = new PluginExecutionException(mojoExecution, null, cause);

     * Reads the metadata from the specified file.
     *
     * @param input The file to deserialize the metadata from, must not be {@code null}.
     * @param options The options to use for deserialization, may be {@code null} to use the default values.
     * @return The deserialized metadata, never {@code null}.
     * @throws IOException If the metadata could not be deserialized.

                        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