Client needs ability to set batch expiration date, for multiple key values.
Existing Client Method:
Task<bool> StringSetAsync(KeyValuePair<RedisKey, RedisValue>[] values, When when = When.Always, CommandFlags flags = CommandFlags.None);
Needed Client Method:
Task<bool> StringSetAsync(KeyValuePair<RedisKey, RedisValue>[] values, TimeSpan? expiry, When when = When.Always, CommandFlags flags = CommandFlags.None);