for (ArtifactRepository repository : remoteRepositories) {
            ArtifactRepositoryPolicy policy = metadata.getPolicy(repository);

            if (policy.isEnabled() && loadMetadata(metadata, repository, localRepository, previousMetadata)) {
                metadata.setRepository(repository);
                selected = repository;
            }
        }

import org.apache.maven.artifact.InvalidRepositoryException;
import org.apache.maven.artifact.repository.ArtifactRepository;
import org.apache.maven.artifact.repository.ArtifactRepositoryFactory;
import org.apache.maven.model.DeploymentRepository;
import org.apache.maven.model.Repository;
import org.apache.maven.plugin.LegacySupport;
import org.apache.maven.repository.RepositorySystem;
import org.codehaus.plexus.PlexusContainer;

                                + " (" + repository.getUrl() + ")");
            }

            return false;
        }

        if (getLogger().isDebugEnabled()) {
            getLogger()
                    .debug("Determining update check for " + artifact + " (" + file + ") from " + repository.getId()
                            + " (" + repository.getUrl() + ")");
        }

                    repository.getId(),
                    repository.getUrl(),
                    repository.getLayout(),
                    repository.getSnapshots(),
                    repository.getReleases());

            repository.setMirroredRepositories(Collections.singletonList(original));

            repository.setId(mirror.getId());
            repository.setUrl(mirror.getUrl());

    Object getKey();

    /**
     * Get the filename of this metadata on the local repository.
     *
     * @param repository the remote repository it came from
     * @return the filename
     */
    String getLocalFilename(ArtifactRepository repository);

    /**
     * Get the filename of this metadata on the remote repository.
     *
     * @return the filename
     */
    String getRemoteFilename();

    /**

     * identifier are added, only the first repository being added will be used.
     *
     * @param repository The repository to add to the internal search chain, must not be {@code null}.
     * @throws InvalidRepositoryException If the repository could not be added (e.g. due to invalid URL or layout).
     */
    void addRepository(Repository repository) throws InvalidRepositoryException;

    /**

        Set<String> repoIds = new HashSet<>();

        for (Repository repository : repositories) {
            validateStringNotEmpty(problems, prefix + ".id", repository.getId(), repository.getUrl());

            validateBannedCharacters(
                    problems, prefix + ".id", Severity.WARNING, repository.getId(), null, ILLEGAL_REPO_ID_CHARS);

    }

    public static RemoteRepository toRemoteRepository(Repository repository) {
        RemoteRepository.Builder builder =
                new RemoteRepository.Builder(repository.getId(), repository.getLayout(), repository.getUrl());
        builder.setSnapshotPolicy(toRepositoryPolicy(repository.getSnapshots()));
        builder.setReleasePolicy(toRepositoryPolicy(repository.getReleases()));
        return builder.build();
    }

     * @param localRepository    local repository
     * @param remoteRepository   remote repository
     * @return {@link List} $lt; {@link ArtifactVersion} >
     * @throws ArtifactMetadataRetrievalException
     *          in case of error while retrieving repository metadata from the repository.
     */
    List<ArtifactVersion> retrieveAvailableVersionsFromDeploymentRepository(

    /**
     * Determines the mirror for the specified repository.
     *
     * @param repository The repository to determine the mirror for, must not be {@code null}.
     * @param mirrors The available mirrors, may be {@code null}.
     * @return The mirror specification for the repository or {@code null} if no mirror matched.
     */
    Mirror getMirror(ArtifactRepository repository, List<Mirror> mirrors);

    /**