public class DependencyRepository {
    private Collection<Dependency> dependencies;
    private static DependencyRepository dependencyRepository;

    // STATIC INIT
    static {
        dependencyRepository = new DependencyRepository();
    }

    private DependencyRepository() {
        this.dependencies = new ArrayList<>();
        initialice();
    }

    private void initialice() {
        add( new Dependency(12, "4 de eso", "4ESO","cuarto de E.S.O.",""));
        ...
    }

    /**
     * This method adds a dependency_list_menu to the repository
     */
    private void add(Dependency dependency) {
        dependencies.add(dependency);
    }

    public static DependencyRepository getDependencyRepository() {
        return dependencyRepository;
    }

    public Collection<Dependency> getAll() {
        return dependencies;
    }
}