Bug 20592: Add tests

Bug 20592: Add tests

NOTE: It isn't really a test, but it does trigger
      the return line which was added to ModItem.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit 619eca1c7aaebf4db6ed170a3cbd14065da79c9d)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit 02860425d9ed9229664dc1d977f1d45ce83bcb50)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>