print Util::Stuff::aaa1->flag; # yields 10
...
our $v = 'Util::Stuff::aaa1';
print $$v->flag;               # yields undef error
...
our $v = 'Util::Stuff::aaa1->flag';
print "$$v\n";                 # yields nothing

##</code><code>##

our $v = 'Util::Stuff::aaa1';
print $v->flag;