#!/usr/bin/perl

use strict;
use warnings;

mainsub();
secsub();
thirdsub();
Frob::fourthsub();

sub mainsub {
    use Data::Dumper;
}

sub secsub {
    my $r = "secsub";
    print Dumper $r;
}

sub thirdsub {
    use Data::Dumper;
    my $r = "thirdsub";
    print Dumper $r;
}

package Frob;

sub fourthsub {
    my $r = "thirdsub";
    print Dumper $r;
}

##</code><code>##

Name "Frob::Dumper" used only once: possible typo at useuse.pl line 31.
$VAR1 = 'secsub';
$VAR1 = 'thirdsub';
print() on unopened filehandle Dumper at useuse.pl line 31.