Unhandled notification with type privacy_token

[qolyla]

I ran ./mdtest -debug and faced with this log lines:

02:22:37.111 [Client/Recv DEBUG] <notification from="[email protected]" id="11715097" t="1655301356" type="privacy_token"><tokens><token jid="[email protected]" t="1655335356" type="trusted_contact">010193c7670dbbabfa5f7d3f5cb2d047a67b4c49dac0f57b96eece64a6b1d1f7431d55</token></tokens></notification>
02:22:37.111 [Client DEBUG] Unhandled notification with type privacy_token

Does anyone know about privacy_token ? I wondered why whatsmeow library doesn't handle this?