docs: public static Class<?> getBoxingClass(Type t) throws BugError
    {
      Type boxingClass = BOXING_MAP.get(t);
      if(boxingClass == null) {
        if(!BOXING_MAP.values().contains(t)) {
          throw new BugError("Trying to get boxing class from not boxed type.");
        }
        boxingClass = t;
      }
      return (Class<?>)boxingClass;
    }