why use TreeSet() to store TaintFlow instance?

[chennbnbnb]

Hi, I notice this code use TreeSet as container of TaintFlow.
TreeSet require TaintFlow must implement interface Comparable.

I wonder if it possible to replace TreeSet with HashSet, because element of HashSet doesn't have to be comparable.

[zhangt2333]

For a sorted result of TaintFlows that helps dump and compare result.

[chennbnbnb]

thx