Added a constraint to the Perl PathQuery example script.
Added a constraint to the Perl PathQuery example script.



Former-commit-id: 3f9dedb218593674bffc22872e31140bb359fe16
julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine