emberjs/data — pull request #1413 by sly7-7 (2013-10-04 08:03:20+00:00)
Title: [doc] hasRecordForId takes a `DS.Model`, not a `String`

Perhaps the real fix is to use modelFor here, but hasRecordForId is also used in `recordIsLoaded` which require a subclass of DS.Model.
To go further, perhaps all public methods should be consistent, I mean take a string parameters and call modelFor.