* @return {@code true} if this range contains the specified version, {@code false} otherwise
     */
    boolean contains(@Nonnull Version version);

    /**
     * Returns a string representation of this version constraint
     * @return the string representation of this version constraint
     */
    @Nonnull
    String asString();

 * supplied by the user of the class. For example, {@code Multiset.Entry.getElement()} returns
 * {@code @ParametricNullness E}, which means:
 *
 * <ul>
 *   <li>{@code getElement} on a {@code Multiset.Entry<@NonNull String>} returns {@code @NonNull
 *       String}.
 *   <li>{@code getElement} on a {@code Multiset.Entry<@Nullable String>} returns {@code @Nullable
 *       String}.
 * </ul>
 *

 * supplied by the user of the class. For example, {@code Multiset.Entry.getElement()} returns
 * {@code @ParametricNullness E}, which means:
 *
 * <ul>
 *   <li>{@code getElement} on a {@code Multiset.Entry<@NonNull String>} returns {@code @NonNull
 *       String}.
 *   <li>{@code getElement} on a {@code Multiset.Entry<@Nullable String>} returns {@code @Nullable
 *       String}.
 * </ul>
 *

     *
     * @throws TransportProviderException if passed in remote repository has invalid remote URL or unsupported protocol.
     */
    @Nonnull
    Transport transport(@Nonnull Session session, @Nonnull RemoteRepository repository);

    return ordering.<T>reverse().<@NonNull S>nullsLast();
  }

  @SuppressWarnings("unchecked") // still need the right way to explain this
  @Override
  public <S extends @Nullable T> Ordering<@Nullable S> nullsFirst() {
    return (Ordering<@Nullable S>) this;
  }

  @Override
  public <S extends @Nullable T> Ordering<@Nullable S> nullsLast() {
    return ordering.<@NonNull S>nullsLast();
  }

  @Override

 * @see DependencyScope
 */
@Experimental
@Immutable
public interface PathScope extends ExtensibleEnum {

    // TODO: what if I simply want all dependencies ?
    @Nonnull
    ProjectScope projectScope();

    @Nonnull
    Set<DependencyScope> dependencyScopes();

    PathScope MAIN_COMPILE = pathScope(
            "main-compile",
            ProjectScope.MAIN,
            DependencyScope.COMPILE_ONLY,

    /**
     * The packaging id.
     */
    @Nonnull
    String id();

    /**
     * The language of this packaging.
     */
    @Nonnull
    default Language language() {
        return type().getLanguage();
    }

    /**
     * The type of main artifact produced by this packaging.
     */
    @Nonnull
    Type type();

    /**

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

/**
 * Base class for requests.
 *
 * @since 4.0.0
 */
@Experimental
abstract class BaseRequest {

    private final Session session;

    protected BaseRequest(@Nonnull Session session) {
        this.session = nonNull(session, "session cannot be null");
    }

    @Nonnull
    public Session getSession() {
        return session;

     *
     * @return the message describing this problem, never {@code null}
     */
    @Nonnull
    String getMessage();

    /**
     * Gets the severity level of this problem.
     *
     * @return the severity level of this problem, never {@code null}
     */
    @Nonnull
    Severity getSeverity();

    /**
     * The different severity levels for a problem, in decreasing order.
     *

      Class<? super @NonNull E> type, E[] emptyArrayForContents, Iterable<? extends E> contents) {
    List<E> setContents = new ArrayList<>();
    for (E e : contents) {
      if (!setContents.contains(e)) {
        setContents.add(e);
      }
    }
    return new MinimalSet<>(type, setContents.toArray(emptyArrayForContents));
  }

  private MinimalSet(Class<? super @NonNull E> type, E... contents) {