def lopUselessLeaves(cls, pn):
""" generated source for method lopUselessLeaves """
usefulComponents = HashSet()
toAdd = Stack()
toAdd.add(pn.getTerminalProposition())
usefulComponents.add(pn.getInitProposition())
for goalProps in pn.getGoalPropositions().values():
toAdd.addAll(goalProps)
for legalProps in pn.getLegalPropositions().values():
toAdd.addAll(legalProps)
while not toAdd.isEmpty():
if usefulComponents.contains(curComp):
continue
usefulComponents.add(curComp)
toAdd.addAll(curComp.getInputs())
allComponents = ArrayList(pn.getComponents())
for c in allComponents:
if not usefulComponents.contains(c):
pn.removeComponent(c)
