def test_add(self):
        """
        L{MemCacheProtocol.add} returns a L{Deferred} which is called back with
        C{True} when the operation succeeds.
        """
        return self._test(
            self.proto.add(b"foo", b"bar"),
            b"add foo 0 0 3\r\nbar\r\n", b"STORED\r\n", True)

        L{MemCacheProtocol.add} returns a L{Deferred} which is called back with
        C{True} when the operation succeeds.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_memcache.py