> tonumber(nil)
nil
> tovector(nil)
stdin:1: unable to cast!
stack backtrace:
[C] function tovector
stdin:1
> toquaternion(nil)
stdin:1: unable to cast!
stack backtrace:
[C] function toquaternion
stdin:1
> touuid(nil)
stdin:1: invalid argument #1 to 'touuid' (string expected, got nil)
stack backtrace:
[C] function touuid
stdin:1