*
     * @return The class realm exposing the Maven API, never {@code null}.
     */
    ClassRealm getMaven4ApiRealm();

    /**
     * Creates a new class realm for the specified project and its build extensions.
     *
     * @param model The model of the project for which to create a realm, must not be {@code null}.

    /**
     * Creates a new settings source backed by the specified string.
     *
     * @param settings The settings' string representation, may be empty or {@code null}.
     */
    public StringSettingsSource(CharSequence settings) {
        this(settings, null);
    }

    /**
     * Creates a new settings source backed by the specified string.
     *

        FATAL, //
        ERROR, //
        WARNING //
    }

    /**
     * Gets the hint about the source of the problem. While the syntax of this hint is unspecified and depends on the
     * creator of the problem, the general expectation is that the hint provides sufficient information to the user to
     * track the problem back to its origin. A concrete example for such a source hint can be the file path or URL from

    }

    @Override
    public CrawlerClientFactory initializeClientFactory(final Supplier<CrawlerClientFactory> creator) {
        if (crawlerClientFactory != null) {
            return crawlerClientFactory;
        }
        final CrawlerClientFactory factory = creator.get();

        final FileAuthenticationService fileAuthenticationService = ComponentUtil.getComponent(FileAuthenticationService.class);

    private final String location;

    private final int hashCode;

    /**
     * Creates a new source backed by the specified string.
     *
     * @param content The String representation, may be empty or {@code null}.
     */
    public StringSource(CharSequence content) {
        this(content, null);
    }

    /**
     * Creates a new source backed by the specified string.
     *

    /**
     * Creates a new model source backed by the specified file.
     *
     * @param pomFile The POM file, must not be {@code null}.
     * @deprecated Use {@link #FileModelSource(Path)} instead.
     */
    @Deprecated
    public FileModelSource(File pomFile) {
        super(pomFile);
    }

    /**
     * Creates a new model source backed by the specified file.
     *

@Deprecated(since = "4.0.0")
public class InvalidRepositoryException extends Exception {

    /**
     * The repository that raised this error, can be {@code null}.
     */
    private Repository repository;

    /**
     * Creates a new exception with specified detail message and cause for the given repository.
     *
     * @param message The detail message, may be {@code null}.

  /** Returns the sample elements that this generate populates its container with. */
  SampleElements<E> samples();

  /**
   * Creates a new container containing the given elements. TODO: would be nice to figure out how to
   * use E... or E[] as a parameter type, but this doesn't seem to work because Java creates an
   * array of the erased type.
   */
  T create(Object... elements);

  /**

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.SampleElements.Unhashables;
import java.util.Collection;
import java.util.List;

/**
 * Creates collections containing unhashable sample elements, to be tested.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

@ElementTypesAreNonnullByDefault
public final class Callables {
  private Callables() {}

  /** Creates a {@code Callable} which immediately returns a preset value each time it is called. */
  public static <T extends @Nullable Object> Callable<T> returning(@ParametricNullness T value) {
    return () -> value;
  }

  /**
   * Creates an {@link AsyncCallable} from a {@link Callable}.
   *