def from_jwe(self, msg, keys):
jwe = JWE()<EOL>_res = jwe.decrypt(msg, keys)<EOL>return self.from_json(_res.decode())<EOL>
Decrypt an encrypted JWT and load the JSON object that was the body
of the JWT into this object.

:param msg: An encrypted JWT
:param keys: Possibly usable keys.
:type keys: list or KeyJar instance
:return: The decrypted message. If decryption failed an exception
    will be raised.