def bip32_seed(self, s):
        """
        Parse a bip32 private key from a seed.
        Return a :class:`BIP32 <pycoin.key.BIP32Node.BIP32Node>` or None.
        """
        pair = parse_colon_prefix(s)
        if pair is None or pair[0] not in "HP":
            return None
        if pair[0] == "H":
            try:
                master_secret = h2b(pair[1])
            except ValueError:
                return None
        else:
            master_secret = pair[1].encode("utf8")
        return self._network.keys.bip32_seed(master_secret)
Parse a bip32 private key from a seed.
        Return a :class:`BIP32 <pycoin.key.BIP32Node.BIP32Node>` or None.