How to create column group in WiredTiger engine in mongodb 2.8? MongoDB 2.8 supports WiredTiger strorage engine, and WiredTiger supports column grouping.

How we can create a collection in mongodb 2.8 with grouped columns?
Although WiredTiger itself does support a column stores, this is not supported with MongoDB.  WiredTiger as implemented in MongoDB only supports LSM trees and the default row-store.