ConcurrentHashMap<Object, Supplier<?>> cache;
        RepositoryCache repositoryCache = session != null ? session.getCache() : null;
        if (repositoryCache == null) {
            return new DefaultModelCache(new ConcurrentHashMap<>());
        } else {
            if (anew) {
                cache = new ConcurrentHashMap<>();
                repositoryCache.put(session, KEY, cache);

import javax.inject.Inject;
import javax.inject.Named;

import java.nio.file.Path;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Stream;

import org.apache.maven.api.Artifact;
import org.apache.maven.api.annotations.Nonnull;
import org.apache.maven.api.di.SessionScoped;

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;

import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Collectors;

import org.apache.maven.api.JavaPathType;
import org.apache.maven.api.Type;
import org.apache.maven.api.annotations.Nonnull;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import com.google.inject.Key;
import com.google.inject.OutOfScopeException;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ForkJoinTask;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicReference;

import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Collectors;

import org.apache.maven.api.Artifact;
import org.apache.maven.api.Lifecycle;
import org.apache.maven.api.Packaging;
import org.apache.maven.api.Project;

import java.nio.file.DirectoryNotEmptyException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import org.apache.maven.api.model.Model;
import org.apache.maven.api.services.Lookup;
import org.apache.maven.eventspy.EventSpy;

import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.Optional;
import java.util.WeakHashMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.function.Supplier;
import java.util.stream.Collectors;

import org.apache.maven.api.Artifact;
import org.apache.maven.api.ArtifactCoordinate;

            } else {
                this.modelPool = null;
                this.transformerContextBuilder = null;
            }
            this.parentCache = new ConcurrentHashMap<>();
            this.modelCache = DefaultModelCache.newInstance(session, true);
        }

        ExecutorService createExecutor(int parallelism) {
            //

   * @since 15.0
   */
  public static <E> Set<E> newConcurrentHashSet() {
    return Collections.newSetFromMap(new ConcurrentHashMap<E, Boolean>());
  }

  /**
   * Creates a thread-safe set backed by a hash map and containing the given elements. The set is
   * backed by a {@link ConcurrentHashMap} instance, and thus carries the same concurrency
   * guarantees.
   *