# TEST.pm
package TEST;

BEGIN {
   our @EXPORT_OK = qw( test_sub );
   our @ISA = qw( Exporter );
   require Exporter;
}

sub test_sub {
  print "Hello, world!\n";
}

##</code><code>##

# TEST2.pm
package TEST2;

use TEST qw( test_sub );

1;

##</code><code>##

# Main script
use TEST2;
use TEST qw( test_sub );

test_sub();