our %debug = ();
$debug{'level'} = 1;
$debug{'stack'}[0] = "main()";

$rv = MyModule::testStack(\%debug);

my @t = $debug{'stack'};
my $CountMain = scalar (@t);
print "$CountMain \n";  # This prints 1

#Now there is another subroutine defined in another module:

sub testStack {
  my $ptr = $_[0];
  my %h = %$ptr;
  my @a = $h{'stack'};
  push (@a, "testStack()");

  my $count = scalar (@a);
  print "$count \n";  # This prints 2

  return 1;
}