def parent(self, idx):
    'Returns the parent group index of the group with the given index\n        or C{None} if the given group is the root.'
    return self._parent[idx]
Returns the parent group index of the group with the given index
or C{None} if the given group is the root.
def parent(self, idx):
    'Returns the parent group index of the group with the given index\n        or C{None} if the given group is the root.'
    return self._parent[idx]