docs: private static boolean isJarURL(final URL rootDirResource) {
  
          final String protocol = rootDirResource.getProtocol();
  
          /**
           * Determine whether the given URL points to a resource in a jar file, that is, has protocol "jar", "zip",
           * "wsjar" or "code-source".
           * <p>
           * "zip" and "wsjar" are used by BEA WebLogic Server and IBM WebSphere, respectively, but can be treated like
           * jar files. The same applies to "code-source" URLs on Oracle OC4J, provided that the path contains a jar
           * separator.
           * *
           */
          return "jar".equals(protocol) || "zip".equals(protocol) || "wsjar".equals(protocol)
                  || ("code-source".equals(protocol) && rootDirResource.getPath().contains(JAR_URL_SEPARATOR));
  
      }