private void findClassesFiles(File dir, ArrayList<File> list) {
    File[] listFiles = dir.listFiles(pathname -> pathname.isDirectory() || pathname.getName().endsWith("class"));
    for (File file : listFiles) {
      if (file.isDirectory()) {
        findClassesFiles(file, list);
      } else {
        list.add(file);
      }
    }
  }
Load classes (interface implementation) from directory.

@param <T>
@param dir  dir with classes, zip or jar's
@param type interface to load
@return
olv-core/src/main/java/pl/otros/logview/api/BaseLoader.java