snmptrap - I don't understand how SNMPv3 traps are sent by the snmptrap utility.

Hey,
 
Please help me with this:
 
1) Does the snmptrap utility send SNMPv3 trap to the master agent? (I
guess not)
2) if not then how does the snmptrap access the USM and VACM modules?
    (these modules are implemented in the master agent)
 
thanks,
erez.