Set `connected` indicator variable.
Set `connected` indicator variable.

Former-commit-id: 2ec6519475aa8563248110162cb14f4ef0c0f579
gsarma/PyOpenWorm,gsarma/PyOpenWorm,travs/PyOpenWorm,openworm/PyOpenWorm,kaustubhcs/PyOpenWorm,openworm/PyOpenWorm,hnunner/PyOpenWorm