def test_allKeysForAuthorizedUser(self):
        """
        If the user is in the mapping provided to
        L{checkers.InMemorySSHKeyDB}, an iterator with all the keys
        is returned by L{checkers.InMemorySSHKeyDB.getAuthorizedKeys}
        """
        keydb = checkers.InMemorySSHKeyDB({b'alice': [b'a', b'b']})
        self.assertEqual([b'a', b'b'], list(keydb.getAuthorizedKeys(b'alice')))

        If the user is in the mapping provided to
        L{checkers.InMemorySSHKeyDB}, an iterator with all the keys
        is returned by L{checkers.InMemorySSHKeyDB.getAuthorizedKeys}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_checkers.py