Reply attribute in access-accept while doing eap-mschapv2

[free.aaa]

>> (3)    * update reply {**
>> **(3) EXPAND %{Class}**
>> **(3)    -->**
>> **(3)     Class = 0x*
>    All that means is there's no Class in the request.  Go look at the
> REST of the debug output to see why.
>
>
Request does not contain Class attribute indeed. I thought that by using 
construction like:
>                 update reply {
>                     Class = "%{Class}"
>                 }
i can grab that attribute from mysql radreply table and insert it in the 
reply.

Anyway why attributes from radreply does not get inserted in 
access-accept when using eap-mschapv2 by default?

Thanks for your help.