for the change (usually before you start working on it).  Trivial changes like typos do not
       require a JIRA issue. Your pull request should address just this issue, without
       pulling in other changes.
 - [ ] Each commit in the pull request should have a meaningful subject line and body.
 - [ ] Format the pull request title like `[MNG-XXX] SUMMARY`,
       where you replace `MNG-XXX` and `SUMMARY` with the appropriate JIRA issue.

 *
 * TODO: move the remote repositories in the requests (plugins will need to access this list somehow)
 * TODO: add request trace so that requests can be linked together and through the resolver
 * TODO: add a Request interface holding session + parent request
 *
 * @since 4.0.0
 */
@Experimental
@ThreadSafe
public interface Session {

    @Nonnull
    Settings getSettings();

        Metadata metadata = request.getMetadata();

        String path;
        if (request.getRepository() == null) {
            path = getPathForLocalMetadata(metadata);
        } else {
            path = getPathForRemoteMetadata(metadata, request.getRepository(), request.getContext());
        }

        }

        if (mojoDescriptor.isProjectRequired() && !session.getRequest().isProjectPresent()) {
            Throwable cause = new MissingProjectException(
                    "Goal requires a project to execute" + " but there is no POM in this directory ("
                            + session.getExecutionRootDirectory() + ")."
                            + " Please verify you invoked Maven from the correct directory.");

    }

    @Override
    public ModelBuilderResult build(ModelBuilderRequest request) throws ModelBuilderException {
        request = fillRequestDefaults(request);
        if (request.getInterimResult() != null) {
            return build(request, request.getInterimResult(), new LinkedHashSet<>());
        } else {
            return build(request, new LinkedHashSet<>());
        }
    }

    @Override
    public Model read(@Nonnull XmlReaderRequest request) throws XmlReaderException {
        nonNull(request, "request");
        Path path = request.getPath();
        URL url = request.getURL();
        Reader reader = request.getReader();
        InputStream inputStream = request.getInputStream();
        if (path == null && url == null && reader == null && inputStream == null) {

    @Override
    public Model read(@Nonnull XmlReaderRequest request) throws XmlReaderException {
        nonNull(request, "request");
        Path path = request.getPath();
        URL url = request.getURL();
        Reader reader = request.getReader();
        InputStream inputStream = request.getInputStream();
        if (path == null && url == null && reader == null && inputStream == null) {

public class DefaultToolchainsXmlFactory implements ToolchainsXmlFactory {
    @Override
    public PersistedToolchains read(@Nonnull XmlReaderRequest request) throws XmlReaderException {
        Objects.requireNonNull(request, "request");
        Reader reader = request.getReader();
        InputStream inputStream = request.getInputStream();
        if (reader == null && inputStream == null) {

public class DefaultToolchainsXmlFactory implements ToolchainsXmlFactory {
    @Override
    public PersistedToolchains read(@Nonnull XmlReaderRequest request) throws XmlReaderException {
        Objects.requireNonNull(request, "request");
        Reader reader = request.getReader();
        InputStream inputStream = request.getInputStream();
        if (reader == null && inputStream == null) {

    @Nonnull
    @Override
    public DependencyCollectorResult collect(@Nonnull DependencyCollectorRequest request)
            throws DependencyCollectorException, IllegalArgumentException {
        nonNull(request, "request");
        InternalSession session = InternalSession.from(request.getSession());

        Artifact rootArtifact;
        DependencyCoordinate root;