Main program:

#!/usr/bin/perl
use strict;
use warnings;
use lib '/home/me/project/temp';
use Lens;
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In '/home/me/project/temp' are Cloud.pm:

package Cloud;
use strict;
use warnings;
1;
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and Lens.pm:

package Lens;
use strict;
use warnings;
use lib '/home/me/project/temp';
use Cloud;
our @ISA = qw(Exporter Cloud);
1;
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Apart from the recommended strict and warnings, all</code> is necessary.