* @return the collection result, never {@code null}
     * @throws DependencyCollectorException if the dependency tree could not be built
     * @throws IllegalArgumentException if an argument is null or invalid
     *
     * @see DependencyCollector#collect(Session, Project)
     * @see DependencyCollector#collect(Session, DependencyCoordinate)
     * @see DependencyCollector#collect(Session, Artifact)
     */
    @Nonnull

import org.apache.maven.api.services.ModelBuilderRequest;
import org.apache.maven.api.services.ModelProblemCollector;

/**
 * Checks the model for missing or invalid values.
 *
 */
public interface ModelValidator {
    /**
     * Checks the specified file model for missing or invalid values. This model is directly created from the POM
     * file and has not been subjected to inheritance, interpolation or profile/default injection.
     *

        if (event.getMetadata().getFile() != null) {
            metadata = event.getMetadata().getFile();
        } else {
            metadata = event.getMetadata();
        }

        String errorType = " is invalid";
        if (exception instanceof FileNotFoundException) {
            errorType = " is inaccessible";
        }

        String msg = "";
        if (exception != null) {

                "jar",
                null,
                new DefaultArtifactHandler("ignore"));
        PluginDescriptor descriptor = new PluginDescriptor();
        descriptor.setGroupId("org.apache.maven.its.plugins.invalid");
        descriptor.setArtifactId("maven-it-plugin");
        descriptor.setVersion("0.1");
        List<String> errors = new ArrayList<>();
        mavenPluginValidator.validate(plugin, descriptor, errors);

    /**
     * Provides new {@link Transport} instance for given {@link RemoteRepository}, if possible.
     *
     * @throws TransportProviderException if passed in remote repository has invalid remote URL or unsupported protocol.
     */
    @Nonnull
    Transport transport(@Nonnull Session session, @Nonnull RemoteRepository repository);

        super(
                mojo.getPluginDescriptor(),
                "The parameters " + format(parameters) + " for goal " + mojo.getRoleHint() + " are missing or invalid");

        this.mojo = mojo;

        this.parameters = parameters;
    }

    private static String format(List<Parameter> parameters) {
        StringBuilder buffer = new StringBuilder(128);

            // MNG-5368: Log a message instead of returning 'null' silently.
            this.logger.error(
                    String.format(
                            "Invalid version specification '%s' creating dependency artifact '%s'.", d.getVersion(), d),
                    e);
            return null;
        }

        Artifact artifact = artifactFactory.createDependencyArtifact(

     * @throws ArtifactResolverException in case of an error
     * @throws IllegalArgumentException in case of parameter {@code buildingRequest} is {@code null} or
     *             parameter {@code mavenArtifact} is {@code null} or invalid
     */
    ArtifactResolverResult resolve(ArtifactResolverRequest request);

    /**
     * @param session {@link Session}
     * @param coordinates array of {@link ArtifactCoordinate}

     * @return an {@code ArtifactCoordinate}, never {@code null}
     * @throws IllegalArgumentException if {@code request} is null or {@code request.session} is null or invalid
     */
    @Nonnull
    ArtifactCoordinate create(@Nonnull ArtifactCoordinateFactoryRequest request);

    /**
     * Creates a coordinate out of string that is formatted like:

                            ((DefaultRemoteRepository) repository).getRepository()));
        } catch (URISyntaxException e) {
            throw new TransportProviderException("Remote repository URL invalid", e);
        } catch (NoTransporterException e) {
            throw new TransportProviderException("Unsupported remote repository", e);
        }
    }