code: public Serializer getSerializer(Class cls) {
      SerializerWrapper w = getSerializerWrapper(cls);
      if (w != null) {
        return w.serializer;
      }
      return null;
    }
docs: Get the serializer instance associated with <code>cls</code> or null if not found.
  
  @param cls object class
  @return serializer instance or null if not found