% reply
0> use Set
1> use BobUtil
2> my $s = Set->new
$res[0] = bless( {
         'items' => {}
       }, 'Set' )

3> $s->add($_) for 1 .. 5
$res[1] = ''

4> BobUtil::set_min($s)
Not an ARRAY reference at BobUtil.pm line 8.