private Map<String, IInternalPapyrusRepository> initializeRepositories() {
    Map<String, IInternalPapyrusRepository> result = Maps.newHashMap();

    for (Repository next : repositoryRegistry.getRepositories()) {
      result.put(next.getURL(), new PapyrusRepository(container, next));
    }

    return result;
  }
  @Override
  public IInternalPapyrusRepository createRepository(String url) {
    if (getRepository(url) != null) {
      throw new IllegalArgumentException("repository already exists"); // $NON-NLS-1$
    }

    Repository repository = RepositoriesFactory.eINSTANCE.createRepository();
    repository.setURL(url);
    repositoryRegistry.getRepositories().add(repository);

    PapyrusRepository result = new PapyrusRepository(container, repository);
    repositories.put(url, result);

    fireElementAddedEvent(result);

    return result;
  }