*
     * @param repositories The original repositories, may be {@code null}.
     * @return The effective repositories or {@code null} if the input was {@code null}.
     */
    List<ArtifactRepository> getEffectiveRepositories(List<ArtifactRepository> repositories);

    /**
     * Determines the mirror for the specified repository.
     *
     * @param repository The repository to determine the mirror for, must not be {@code null}.