PURPOSE
Tests that the one-argument form of does works with lexical $_, using a Perl 5.10 given block.
In Perl 5.17.x and above, given no longer uses lexical $_ but this test should continue to work.
AUTHOR
Toby Inkster <tobyink@cpan.org>.
COPYRIGHT AND LICENCE
This software is copyright (c) 2012-2014 by Toby Inkster.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.