code: public static void preload(@NonNull ClassLoader classLoader) {
        Resource r = new ClasspathResource("META-INF/preload.classes", classLoader);
        if (r.exists()) {
           try {
              r.readLines().forEach(ReflectionUtils::getClassForNameQuietly);
           } catch (IOException e) {
              e.printStackTrace();
           }
        }
     }
docs: Preloads using the given class loader.
  
  @param classLoader the class loader to scan for the preload.classes file