prometheus/prometheus — pull request #166 by matttproud (2013-04-21 17:55:23+00:00)
Title: Wrap dto.SampleKey with business logic type.

The curator work can be done easier if dto.SampleKey is no longer
directly accessed but rather has a higher level type around it that
captures a certain modicum of business logic. This doesn't look
terribly interesting today, but it will get more so.