add checkstyle
add checkstyle


Former-commit-id: 144c50d5b85e25e91ee69fbcb387888264bd6cea
julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine