private Region createRegion(String regionName, String... bundleSymbolicNames)
     throws BundleException {
   Region region = this.digraph.createRegion(regionName);
   for (String bundleSymbolicName : bundleSymbolicNames) {
     Bundle stubBundle = createBundle(bundleSymbolicName);
     region.addBundle(stubBundle);
   }
   this.regions.put(regionName, region);
   return region;
 }