#! perl -w 

use strict;
use Params::Check qw(check last_error);

my $verbose = 1;

my_func( { test_block => sub {$b cmp $a} } );

sub my_func {
   my $sort_function;
   my $tmpl = {
      test_block => {
         required => 1,
         defined => 1, 
         default => sub {$a cmp $b}, 
         strict_type => 1, 
         store => \$sort_function}
   };
   check($tmpl, shift, $verbose) 
   		or warn ('problem with check: ' . Params::Check::last_error());
   my @stuff = qw(foo bie bletch a z);
   @stuff = sort $sort_function @stuff;
   print join "\n", @stuff;
}