use warnings;
use strict;

use version;

BEGIN {
    use base 'Mock::Sub';
    my $v = version->parse($Mock::Sub::VERSION);
    if ($v < version->parse(1.07)){
        die "Version '$v' of Mock::Sub isn't 1.07 or greater";
    }
}

##</code><code>##

$ perl base.pl 
Version '1.06' of Mock::Sub isn't 1.07 or greater at base.pl line 10.
BEGIN failed--compilation aborted at base.pl line 12.

$ cpanm Mock::Sub
--> Working on Mock::Sub
Fetching http://www.cpan.org/authors/id/S/ST/STEVEB/Mock-Sub-1.09.tar.gz ... OK
Configuring Mock-Sub-1.09 ... OK
Building and testing Mock-Sub-1.09 ... OK
Successfully installed Mock-Sub-1.09 (upgraded from 1.06)
1 distribution installed

$ perl base.pl