code: private void initCompositeBundleMap(List<JoinableResourceBundle> bundles) {
  		for (JoinableResourceBundle bundle : bundles) {
  			if (bundle.isComposite()) {
  				List<JoinableResourceBundle> childBundles = ((CompositeResourceBundle) bundle).getChildBundles();
  				for (JoinableResourceBundle childBundle : childBundles) {
  					List<JoinableResourceBundle> associatedBundles = compositeResourceBundleMap
  							.get(childBundle.getId());
  					if (associatedBundles == null) {
  						associatedBundles = new ArrayList<>();
  					}
  					associatedBundles.add(bundle);
  					compositeResourceBundleMap.put(childBundle.getId(), associatedBundles);
  				}
  			}
  		}
  	}
docs: Initialize the composite bundle map
  
  @param bundles
  list of resource bundle