Pass en empty datum if nothing was computed
Pass en empty datum if nothing was computed

mathstuf/sprokit,mathstuf/sprokit,Kitware/sprokit,mathstuf/sprokit,linus-sherrill/sprokit,Kitware/sprokit,mathstuf/sprokit,Kitware/sprokit,Kitware/sprokit,linus-sherrill/sprokit,linus-sherrill/sprokit,linus-sherrill/sprokit