/**
 * Base class for requests.
 *
 * @since 4.0.0
 */
@Experimental
abstract class BaseRequest<S extends ProtoSession> implements Request<S> {

    private final S session;
    private final RequestTrace trace;

    protected BaseRequest(@Nonnull S session) {
        this(session, null);
    }

    protected BaseRequest(@Nonnull S session, RequestTrace trace) {

            return new DefaultVersionResolverRequest(session, trace, artifactCoordinates, repositories);
        }

        private static class DefaultVersionResolverRequest extends BaseRequest<Session>
                implements VersionResolverRequest {
            private final ArtifactCoordinates artifactCoordinates;
            private final List<RemoteRepository> repositories;

            return new DefaultArtifactResolverRequest(session, trace, coordinates, repositories);
        }

        private static class DefaultArtifactResolverRequest extends BaseRequest<Session>
                implements ArtifactResolverRequest {
            @Nonnull
            private final Collection<? extends ArtifactCoordinates> coordinates;

            @Nullable

                    session, trace, groupId, artifactId, version, classifier, extension, type, coordinateString);
        }

        private static class DefaultArtifactFactoryRequestArtifact extends BaseRequest<Session>
                implements ArtifactCoordinatesFactoryRequest {
            private final String groupId;
            private final String artifactId;
            private final String version;

                    scope,
                    optional,
                    exclusions);
        }

        private static class DefaultDependencyCoordinatesFactoryRequest extends BaseRequest<Session>
                implements DependencyCoordinatesFactoryRequest {
            private final String groupId;
            private final String artifactId;
            private final String version;

            return new DefaultVersionResolverRequest(session, trace, artifactCoordinates, repositories, nature);
        }

        private static class DefaultVersionResolverRequest extends BaseRequest<Session>
                implements VersionRangeResolverRequest {
            private final ArtifactCoordinates artifactCoordinates;
            private final List<RemoteRepository> repositories;

                    session, trace, path, source, allowStubModel, recursive, processPlugins, repositories);
        }

        private static class DefaultProjectBuilderRequest extends BaseRequest<Session>
                implements ProjectBuilderRequest {
            private final Path path;
            private final Source source;
            private final boolean allowStubModel;

                    repositoryMerging,
                    repositories,
                    lifecycleBindingsInjector);
        }

        private static class DefaultModelBuilderRequest extends BaseRequest<Session> implements ModelBuilderRequest {
            private final RequestType requestType;
            private final boolean locationTracking;
            private final boolean recursive;

                    pathScope,
                    pathTypeFilter,
                    targetVersion,
                    repositories);
        }

        static class DefaultDependencyResolverRequest extends BaseRequest<Session>
                implements DependencyResolverRequest {

            static final class AlwaysTrueFilter implements Predicate<PathType> {
                @Override