use strict;
use warnings;

package TestHarness;

BEGIN {
   our @EXPORT_OK = qw( unlink );
   require Exporter;
   *import = \&Exporter::import;
}

sub unlink {
   print("PRE unlink\n");
   # Don't forget to properly handle context.
   my $rv = unlink(@_);
   print("POST unlink\n");
   return $rv;
}

1;

##</code><code>##

use strict;
use warnings;

BEGIN {
   # Parse options or something.
   $::TESTING = 1;
}

use if $::TESTING, TestHarness => qw( unlink );

unlink();

##</code><code>##

PRE unlink
POST unlink