al.krinker (16) [Avatar] Offline
"Steps 1, 2 and 3 above sum up the implementation of the HeatMapBuilder bolt."

While we have most of the stuff here, I did not see declareOutputFields method.

Since we are setting up in Step 1, consider adding this method here for completeness.
matthew.jankowski (17) [Avatar] Offline
This was intentionally left out as that code is meant to address the 3 specific steps that come before it. I can see how this may lead to some confusion, but if you look at the source code, everything should be there. Thanks for the comment.