SNMP v3 gets with SnmpSharpNet and AES192/AES256

Question

I'm trying to use SnmpSharpNet to make and SNMP v3 get with a privacy algorithm of AES192 or AES256.

I cannot get a positive response back. I do for AES128 and DES though.

I noticed in iReasoning MIB Browser tool there is an option (checkbox) labeled: "AES192/256 Key expansion with engine ID”

I'm betting that is the piece I'm missing. Does anyone know how to configure SnmpSharpNet to do this for AES192 or AES256?

This is how I'm setting up my SecureAgentParameters. Which works fine with PrivacyProtocols.AES128 and PrivacyProtocols.DES.

            param.authPriv (
                "admin",
                AuthenticationDigests.MD5, @"12345678@",
                PrivacyProtocols.AES256, @"12345678@");

Any help would be appreciated. Thank you.