multi_set
同时写一条hashkey的多条sortkey数据
def multi_set(self, hash_key, sortkey_value_dict, ttl=0, timeout=0):
"""
Set multiple sort_keys-values under hash_key to be stored.
:param hash_key: (str) which hash key used for this API.
:param sortkey_value_dict: (dict) <sort_key, value> pairs in dict.
:param ttl: (int) ttl(time to live) in seconds of these data.
:param timeout: (int) how long will the operation timeout in milliseconds.
if timeout > 0, it is a timeout value for current operation,
else the timeout value specified to create the instance will be used.
:return: (tuple<error_types.code.value, _>) (code, ign)
code: error_types.ERR_OK.value when data stored succeed.
ign: useless, should be ignored.
"""