private final AtomicReference<List<Entry>> entries = new AtomicReference<>(new CopyOnWriteArrayList<>());

    @Override
    public void log(Level level, String message, Throwable error) {
        requireNonNull(level, "level");
        requireNonNull(message, "message");
        entries.get().add(new Entry(level, message, error));
    }

    @Override
    public List<Entry> drain() {

      super.addAll(elements);
      return this;
    }

    @CanIgnoreReturnValue
    Builder<E> combine(Builder<E> other) {
      requireNonNull(impl);
      requireNonNull(other.impl);
      /*
       * For discussion of requireNonNull, see the comment on the field.
       *
       * (And I don't believe there's any situation in which we call x.combine(y) when x is a plain

        }

        public Builder withStartTime(@Nonnull Instant startTime) {
            this.startTime = requireNonNull(startTime, "startTime");
            return this;
        }

        public Builder withTopDirectory(@Nonnull Path topDirectory) {
            this.topDirectory = requireNonNull(topDirectory, "topDirectory");
            return this;
        }

        public ProtoLookup build() {
            return new ProtoLookup(components);
        }

        public <T> Builder addMapping(Class<T> type, T component) {
            requireNonNull(type, "type");
            requireNonNull(component, "component");
            if (components.put(type, component) != null) {
                throw new IllegalStateException("Duplicate mapping for type: " + type.getName());
            }

            @Nullable List<RemoteRepository> repositories,
            @Nullable Nature nature) {
        return builder()
                .session(requireNonNull(session, "session cannot be null"))
                .artifactCoordinates(requireNonNull(artifactCoordinates, "artifactCoordinates cannot be null"))
                .repositories(repositories)
                .nature(nature)
                .build();
    }

import static java.util.Objects.requireNonNull;

/**
 * Maven specific transformer.
 */
@Singleton
@Named
final class MavenTransformer implements ArtifactTransformer {
    private final TransformerManager transformerManager;

    @Inject
    MavenTransformer(TransformerManager transformerManager) {
        this.transformerManager = requireNonNull(transformerManager);
    }

    @Override

        return builder(requireNonNull(request, "request cannot be null"))
                .source(requireNonNull(source, "source cannot be null"))
                .build();
    }

    @Nonnull
    static ModelBuilderRequest build(@Nonnull Session session, @Nonnull ModelSource source) {
        return builder()
                .session(requireNonNull(session, "session cannot be null"))

@Deprecated(since = "4.0.0")
public class DefaultToolchainsReader implements ToolchainsReader {

    @Override
    public PersistedToolchains read(File input, Map<String, ?> options) throws IOException {
        Objects.requireNonNull(input, "input cannot be null");

        try (InputStream in = Files.newInputStream(input.toPath())) {
            InputSource source = InputSource.of(input.toString());

        return modelIds;
    }

    public DefaultModelBuildingResult addModelId(String modelId) {
        // Intentionally notNull because Super POM may not contain a modelId
        Objects.requireNonNull(modelId, "modelId cannot null");

        modelIds.add(modelId);

        return this;
    }

    @Override
    public Model getRawModel() {
        return rawModels.get(modelIds.get(0));
    }

import org.apache.maven.api.annotations.Nonnull;
import org.apache.maven.api.annotations.NotThreadSafe;
import org.apache.maven.api.annotations.Nullable;

import static java.util.Objects.requireNonNull;

/**
 *
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface ArtifactFactoryRequest extends Request<Session> {

    String getGroupId();

    String getArtifactId();