import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.ThreadSafe;

/**
 * Marker interface for all services provided by the {@link Session}.
 * <p>
 * Services can be retrieved from the session using the
 * {@link Session#getService(Class)} method.
 *
 * @since 4.0.0
 * @see Session#getService(Class)
 */
@Experimental
@ThreadSafe

        }
    }

    @Override
    public ResolutionGroup retrieve(
            Artifact artifact, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories)
            throws ArtifactMetadataRetrievalException {
        return retrieve(artifact, localRepository, remoteRepositories, false);
    }

    public ResolutionGroup retrieve(
            Artifact artifact,

 * create a dependency graph. First, only the root dependency can be given. Second, a root dependency and direct
 * dependencies can be specified in which case the specified direct dependencies are merged with the direct dependencies
 * retrieved from the artifact descriptor of the root dependency. And last, only direct dependencies can be specified in
 * which case the root node of the resulting graph has no associated dependency.
 *
 * @since 4.0.0

 */
@Deprecated
public interface ArtifactMetadataSource extends org.apache.maven.repository.legacy.metadata.ArtifactMetadataSource {

    ResolutionGroup retrieve(MetadataResolutionRequest request) throws ArtifactMetadataRetrievalException;

    ResolutionGroup retrieve(
            Artifact artifact, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories)
            throws ArtifactMetadataRetrievalException;

     *
     * @param key the key for which to retrieve the session data, must not be {@code null}
     * @return the session data associated with the key or {@code null} if none
     */
    @Nullable
    <T> T get(@Nonnull Key<T> key);

    /**
     * Retrieve of compute the data associated with the specified key.
     *
     * @param key the key for which to retrieve the session data, must not be {@code null}

import org.apache.maven.artifact.repository.metadata.RepositoryMetadataStoreException;

/**
 * Contains metadata about an artifact, and methods to retrieve/store it from an artifact repository.
 * TODO merge with artifactmetadatasource
 * TODO retrieval exception not appropriate for store
 *
 */
public interface ArtifactMetadata {
    /**
     * Whether this metadata should be stored alongside the artifact.
     *

 */
package org.apache.maven.rtinfo;

/**
 * Provides information about the current Maven runtime.
 *
 * @since 3.0.2
 */
public interface RuntimeInformation {

    /**
     * Retrieves the current Maven version, for example "3.0.2".
     *
     * @return The current Maven version or an empty string if unknown, never {@code null}.
     */
    String getMavenVersion();

    /**

    /**
     * Obtain the {@link Type} from the specified {@code id}.
     * If no type is known for {@code id}, the registry will
     * create a custom {@code Type} for it.
     *
     * @param id the id of the type to retrieve
     * @return the type
     */
    @Nonnull
    @Override
    default Type require(@Nonnull String id) {

                                    // We retrieve the POM below in the retrieval step.
                                    manageArtifact(child, managedVersions, listeners);

                                    // Also, we need to ensure that any exclusions it presents are
                                    // added to the artifact before we retrieve the metadata

                artifactVersions = Collections.emptyList();
            }
            return artifactVersions;
        }

        public ResolutionGroup retrieve(MetadataResolutionRequest request) throws ArtifactMetadataRetrievalException {
            return retrieve(request.getArtifact(), request.getLocalRepository(), request.getRemoteRepositories());
        }