DynamoDS/Dynamo — pull request #3060 by ke-yu (2014-11-13 07:59:12+00:00)
Title: Fix magn5407: GroupByKey fails in 0.7.3 

Fix defect [MAGN5407: GroupByKey fails in 0.7.3 ] (http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-5407)

This is because an internal function that used in ``GroupByKey`` should be ``__Apply()`` instead of ``Apply()``.

@sharadkjaiswal please review the change.