code:     protected void checkIllegalTypes(DeserializationContext ctxt, JavaType type,
              BeanDescription beanDesc)
          throws JsonMappingException
      {
          // There are certain nasty classes that could cause problems, mostly
          // via default typing -- catch them here.
          String full = type.getRawClass().getName();
  
          if (_cfgIllegalClassNames.contains(full)) {
              throw JsonMappingException.from(ctxt,
                      String.format("Illegal type (%s) to deserialize: prevented for security reasons", full));
          }
      }
  