sub routine { 
   my($thingy, $tx) = @_; # $thingy is not used
   print "routine: $tx\n";
}

my $ref = \&routine; # take a reference to the sub
my $pkg = "main";
my $obj = bless do { \my $x };

# we could also say...
#   my $pkg = __PACKAGE__;
# ...to get any package we are in in compile time