code: public static ExtensionInfo load(String className, ClassLoader classLoader) {
          try (InputStream input = classLoader.getResourceAsStream(className.replace('.', '/') + ".class")) {
              ExtensionInfo info = new ExtensionInfo(className);
              new ClassReader(input).accept(new ExtensionVisitor(info), ClassReader.SKIP_DEBUG);
  
              return info;
          } catch (IOException e) {
              log.error(e.getMessage(), e);
              return null;
          }
      }
docs: Load an {@link ExtensionInfo} for a certain class.
  
  @param className absolute class name
  @param classLoader class loader to access the class
  @return the {@link ExtensionInfo}, if the class was annotated with an {@link Extension}, otherwise null