code: private synchronized void initCache() {
  
      if (this.cache == null) {
        ClasspathFolder rootFolder = new ClasspathFolder(null, "");
        Set<String> resourceNames = this.reflectionUtil.findResourceNames("", true, ConstantFilter.getInstance(true));
        List<ClasspathFile> fileList = new ArrayList<>(resourceNames.size());
        for (String resource : resourceNames) {
          ResourcePathNode<Void> path = ResourcePathNode.create(resource);
          ClasspathFolder parent = createFolderRecursive(path.getParent(), rootFolder);
          ClasspathFile file = new ClasspathFile(parent, path.getName());
          parent.children.add(file);
          fileList.add(file);
        }
        this.cache = new Cache(rootFolder, fileList);
      }
    }
docs: Scans the entire classpath and initializes the {@link #getReflectionUtil() root}.