def get_private(self):
encoded = "<STR_LIT>" % (self.brainkey, self.sequence)<EOL>a = _bytes(encoded)<EOL>s = hashlib.sha256(hashlib.sha512(a).digest()).digest()<EOL>return PrivateKey(hexlify(s).decode("<STR_LIT:ascii>"), prefix=self.prefix)<EOL>
Derive private key from the brain key and the current sequence
            number