206,211c206,207
< def get_parent(self):
< parent_set = set(v._parent for v in self)
< if len(parent_set) != 1:
< raise RuntimeError, \
< "SimObjectVector elements have inconsistent parent value."
< return parent_set.pop()
---
> def has_parent(self):
> return reduce(lambda x,y: x and y, [v.has_parent() for v in self])