def append(self, key, val, time=<NUM_LIT:0>, min_compress_len=<NUM_LIT:0>):
return self._set("<STR_LIT>", key, val, time, min_compress_len)<EOL>
Append the value to the end of the existing key's value.

        Only stores in memcache if key already exists.
        Also see L{prepend}.

        @return: Nonzero on success.
        @rtype: int