After a week's waiting, my little MacBook Pro had come back home on Sunday safe and sound, did not lose a single piece of useful data. As soon as I got him back, I start finishing up the issue sensor to ready for commit.
After a serious consideration, I decide to discard the RSS feed as data source completely, because firstly it does not provide much more useful information than extract data from issue summary table, secondly the RSS feed service seems more unstable than the issue tracking system,which make the sensor unstable as well, and thirdly it make the code more complex and hard to validate data completeness. My opinion is, if the user really don't want to miss a single update information, just run the sensor as often as he like.
I also found it kind of hard to test the issue sensor, because it is almost impossible to have a fully controllable and repeatable test environment. The content of Google Project Hosting will keep changing. For current state, I test it by run it twice, and make sure the first run generate some issue data, and the second run did not detect any changes. The better way to exam if the sensor working properly is to actually use it. So my job this week is to work on DailyProjectData to use the issue sensordata to generate issue DPD.