mesos/spark — pull request #251 by JoshRosen (2012-10-07 08:19:47+00:00)
Title: Document Dependency classes and make minor interface improvements

These commits add API documentation for the `Dependency` classes and make two interface changes:

- Remove the unused `isShuffle` field from `Dependency`
- Change the type of `ShuffleDependency.aggregator` to an `Option` to communicate that the aggregator is optional. Currently, the absence of an aggregator is expressed using `Aggregator[K, V, V](null, null, null, false)`, which is a bit of a hack.

Will these two changes introduce backwards-compatibility problems in the API?