Add code to extract blocks from a generic block
Add code to extract blocks from a generic block

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