class PropertyExtensionPackageProvider implements ExtensionPackageProvider {

  @Override
  public Set<String> getPackageNames(ConfigurableEnvironment env) {
    @SuppressWarnings("unchecked")
    Set<String> packageNames = env.getProperty("extension-packages", Set.class);
    return packageNames == null ? Collections.<String>emptySet() : packageNames;
  }

}