@Nullable public static Class<?> box(@Nullable Class<?> cls){
  if (cls == null)   return null;
  if (!cls.isPrimitive())   return cls;
  return boxedClsMap.get(cls);
}

@ Nullable public static Class < ? > box ( @ Nullable Class < ? > cls ) { if ( cls == null ) return null ; if ( ! cls . isPrimitive ( ) ) return cls ; return boxedClsMap . get ( cls ) ; }
gets wrapper class for a primitive type .
