* future version of {@code com.google.common.base.Supplier} will be made to <i>extend</i> {@code
 * java.util.function.Supplier}, making conversion code necessary only in one direction. At that
 * time, this interface will be officially discouraged.
 *
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

   * words, the new supplier's value will be computed by retrieving the value from {@code supplier},
   * and then applying {@code function} to that value. Note that the resulting supplier will not
   * call {@code supplier} or invoke {@code function} until it is called.
   */
  public static <F extends @Nullable Object, T extends @Nullable Object> Supplier<T> compose(
      Function<? super F, T> function, Supplier<F> supplier) {

   * words, the new supplier's value will be computed by retrieving the value from {@code supplier},
   * and then applying {@code function} to that value. Note that the resulting supplier will not
   * call {@code supplier} or invoke {@code function} until it is called.
   */
  public static <F extends @Nullable Object, T extends @Nullable Object> Supplier<T> compose(
      Function<? super F, T> function, Supplier<F> supplier) {

        public int hashCode() {
            return hash;
        }
    }

    static class CachingSupplier<T> implements Supplier<T> {
        final Supplier<T> supplier;
        volatile Object value;

        CachingSupplier(Supplier<T> supplier) {
            this.supplier = supplier;
        }

        @Override
        @SuppressWarnings({"unchecked", "checkstyle:InnerAssignment"})
        public T get() {

  }

  public static <E extends @Nullable Object> SpliteratorTester<E> of(
      Supplier<Spliterator<E>> spliteratorSupplier) {
    return new SpliteratorTester<>(
        ImmutableSet.of(() -> new GeneralSpliteratorOfObject<>(spliteratorSupplier.get())));
  }

  /**
   * @since 28.1
   */
  public static SpliteratorTester<Integer> ofInt(Supplier<Spliterator.OfInt> spliteratorSupplier) {
    return new SpliteratorTester<>(

 * model builder.
 *
 */
public interface ModelCache {

    <T> T computeIfAbsent(String groupId, String artifactId, String version, String tag, Supplier<T> data);

    <T> T computeIfAbsent(Source path, String tag, Supplier<T> data);

import java.util.ArrayList;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Supplier;
import java.util.stream.Collectors;

import com.google.inject.AbstractModule;
import com.google.inject.binder.AnnotatedBindingBuilder;
import com.google.inject.name.Names;

                }
            }
            return model;
        }

        public Model computeIfAbsent(Supplier<Model> supplier) {
            if (!set) {
                synchronized (this) {
                    if (!set) {
                        this.set = true;
                        this.model = supplier.get();
                        this.notifyAll();
                    }
                }
            }

 * memorized and kept as long as supplier instance is kept open.
 * <p>
 * This class is not thread safe and must be used from one thread only, while the constructed {@link RepositorySystem}
 * is thread safe.
 * <p>
 * Important: Given the instance of supplier memorizes the supplier {@link RepositorySystem} instance it supplies,

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
 * of sessions, use {@link CloseableSession#close()} method on built instance(s).