code: @Override
      public synchronized List<BundleWebJarLib> addingBundle(Bundle bundle, BundleEvent bundleEvent) {
          Enumeration<URL> e = bundle.findEntries(WEBJAR_LOCATION, "*", true);
          if (e == null) {
              // No match
              return Collections.emptyList();
          }
          List<BundleWebJarLib> list = new ArrayList<>();
          while (e.hasMoreElements()) {
              String path = e.nextElement().getPath();
              if (path.endsWith("/")) {
                  Matcher matcher = WEBJAR_ROOT_REGEX.matcher(path);
                  if (matcher.matches()) {
                      String name = matcher.group(1);
                      String version = matcher.group(2);
                      final BundleWebJarLib lib = new BundleWebJarLib(name, version, bundle);
                      logger().info("Web Jar library ({}) found in {} [{}]", lib,
                              bundle.getSymbolicName(),
                              bundle.getBundleId());
                      list.add(lib);
                  }
              }
          }
  
          addWebJarLibs(list);
  
          return list;
      }
docs: A bundle just arrived (and / or just becomes ACTIVE). We need to check if it contains 'webjar libraries'.
  
  @param bundle      the bundle
  @param bundleEvent the event
  @return the list of webjar found in the bundle, empty if none.