Added some comments
Added some comments


Former-commit-id: e41e5d09fa7fb7ac120a957fca97e4412099a909
julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine