code: def nodeids(self, ivs=None, quantifier=None):
          
          if ivs is None:
              nids = list(self._nodeids)
          else:
              _vars = self._vars
              nids = []
              for iv in ivs:
                  if iv in _vars and IVARG_ROLE in _vars[iv]['refs']:
                      nids.extend(_vars[iv]['refs'][IVARG_ROLE])
                  else:
                      raise KeyError(iv)
          if quantifier is not None:
              nids = [n for n in nids if self.ep(n).is_quantifier()==quantifier]
          return nids
docs: Return the list of nodeids given by *ivs*, or all nodeids.
  
          Args:
              ivs: the intrinsic variables of the predications to select;
                  if `None`, return all nodeids (but see *quantifier*)
              quantifier: if `True`, only return nodeids of quantifiers;
                  if `False`, only return non-quantifiers; if `None`
                  (the default), return both