return modelIds;
    }

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

        modelIds.add(modelId);

        return this;
    }

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

import org.eclipse.aether.util.graph.transformer.SimpleOptionalitySelector;
import org.eclipse.aether.util.repository.SimpleArtifactDescriptorPolicy;

import static java.util.Objects.requireNonNull;

/**
 * A simple {@link Supplier} of {@link SessionBuilder} instances, that on each call supplies newly
 * constructed instance. To create session out of builder, use {@link SessionBuilder#build()}. For proper closing

    private final DefaultLifecycles defaultLifeCycles;

    @Inject
    public DefaultLifecyclePluginAnalyzer(Lookup lookup, DefaultLifecycles defaultLifeCycles) {
        this.lookup = requireNonNull(lookup);
        this.defaultLifeCycles = requireNonNull(defaultLifeCycles);
    }

    // These methods deal with construction intact Plugin object that look like they come from a standard

import static java.util.Objects.requireNonNull;

/**
 * A class building reverse tree using {@link CollectStepData} trace data provided in {@link RepositoryEvent}
 * events fired during collection.
 *
 * @since 3.9.0
 */
class ReverseTreeRepositoryListener extends AbstractRepositoryListener {
    @Override
    public void artifactResolved(RepositoryEvent event) {
        requireNonNull(event, "event cannot be null");

@ElementTypesAreNonnullByDefault
final class Platform {
  private Platform() {}

  /** Returns a thread-local 1024-char array. */
  static char[] charBufferFromThreadLocal() {
    // requireNonNull accommodates Android's @RecentlyNullable annotation on ThreadLocal.get
    return requireNonNull(DEST_TL.get());
  }

  /**
   * A thread-local destination buffer to keep us from creating new buffers. The starting size is

        out.append(format.normalizeFirstWord(s.substring(i, j)));
      } else {
        requireNonNull(out).append(format.normalizeWord(s.substring(i, j)));
      }
      out.append(format.wordSeparator);
      i = j + wordSeparator.length();
    }
    return (i == 0)
        ? format.normalizeFirstWord(s)
        : requireNonNull(out).append(format.normalizeWord(s.substring(i))).toString();
  }

  /**

  private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
    stream.defaultReadObject();
    keyTypeOrObjectUnderJ2cl = (Class<K>) requireNonNull(stream.readObject());
    valueTypeOrObjectUnderJ2cl = (Class<V>) requireNonNull(stream.readObject());
    setDelegates(
        new EnumMap<K, V>(keyTypeOrObjectUnderJ2cl), new EnumMap<V, K>(valueTypeOrObjectUnderJ2cl));

import org.apache.maven.project.MavenProject;
import org.apache.maven.toolchain.model.ToolchainModel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static java.util.Objects.requireNonNull;

/**
 */
@Named
@Singleton
public class DefaultToolchainManager implements ToolchainManager {
    protected final Logger logger; // TODO this class is extended, needs refactoring

        this.mavenProject = Objects.requireNonNull(mavenProject, "mavenProject cannot be null");
        this.pomFile = pomFile;
        context = JXPathContext.newContext(mavenProject.getModel());
    }

    public PomTestWrapper(MavenProject mavenProject) {
        this.mavenProject = Objects.requireNonNull(mavenProject, "mavenProject cannot be null");

    @Override
    @CheckForNull
    protected EndpointPair<N> computeNext() {
      while (true) {
        if (successorIterator.hasNext()) {
          // requireNonNull is safe because successorIterator is empty until we set this.node.
          return EndpointPair.ordered(requireNonNull(node), successorIterator.next());
        }
        if (!advance()) {
          return endOfData();
        }
      }
    }
  }

  /**