code: def hierarchical_key(self, s):
          
          s = parseable_str(s)
          for f in [self.bip32_seed, self.bip32_prv, self.bip32_pub,
                    self.electrum_seed, self.electrum_prv, self.electrum_pub]:
              v = f(s)
              if v:
                  return v
docs: Parse text as some kind of hierarchical key.
          Return a subclass of :class:`Key <pycoin.key.Key>`, or None.