code: public static Class<?> getPrimitiveClass(final Object object) {
  
      if (object == null) {
        return null;
      }
      return getPrimitiveClass(object.getClass());
    }
docs: Returns given object class primitive class or self class.<br>
  if given object class is 8 wrapper class then return primitive class.<br>
  if given object class is null return null.
  
  @param object object to be handle.
  @return given object class primitive class or self class.