def test_unicodeKey(self):
        """
        Using a non-string key as argument to commands raises an error.
        """
        d1 = self.assertFailure(self.proto.set(u"foo", b"bar"), ClientError)
        d2 = self.assertFailure(self.proto.increment(u"egg"), ClientError)
        d3 = self.assertFailure(self.proto.get(1), ClientError)
        d4 = self.assertFailure(self.proto.delete(u"bar"), ClientError)
        d5 = self.assertFailure(self.proto.append(u"foo", b"bar"), ClientError)
        d6 = self.assertFailure(
            self.proto.prepend(u"foo", b"bar"), ClientError)
        d7 = self.assertFailure(
            self.proto.getMultiple([b"egg", 1]), ClientError)
        return gatherResults([d1, d2, d3, d4, d5, d6, d7])

        Using a non-string key as argument to commands raises an error.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_memcache.py