code: private Map<AddonId, AddonRepository> getInstalledAddons()
     {
        Map<AddonId, AddonRepository> addons = new HashMap<>();
        for (AddonRepository repository : getRepositories())
        {
           List<AddonId> listEnabled = repository.listAll();
           for (AddonId addonId : listEnabled)
           {
              addons.put(addonId, repository);
           }
        }
        return addons;
     }
docs: Returns a {@link Map} of the installed addons with the a key of {@link AddonId} and the value of
  {@link AddonRepository} indicating in which repository the addon is installed.