'A certificate and keypair written by ``UserCredential.initialize``
can be loaded back from the individual files, with the username
extracted from the subject common name.'

def test_from_files(self):

    certificate_path = self.credential.credential.path.child('alice.crt')
    key_path = self.credential.credential.path.child('alice.key')
    user_credential = UserCredential.from_files(certificate_path, key_path)
    self.assertEqual(u'alice', user_credential.username)
