print One::foo();
{
    my $count = Count->new;
    no warnings 'redefine';
    local *One::foo = sub { $count->{x} = 'x'; return "baz\n"; };
    print One::foo();
}
print One::foo();

##</code><code>##

package One::Debug;
our @ISA = 'One';
sub foo {
    return "baz\n";
}
1;