func (s *ManifoldSuite) TestOutputSuccess(c *gc.C) {
source := leadership.DummyTrackerWorker()
var target leadership.Tracker
err := s.manifold.Output(source, &target)
c.Check(err, jc.ErrorIsNil)
c.Check(target, gc.Equals, source)
}
func (s *ManifoldSuite) TestOutputBadTarget(c *gc.C) {
var target interface{}
err := s.manifold.Output(leadership.DummyTrackerWorker(), &target)
c.Check(target, gc.IsNil)
c.Check(err.Error(), gc.Equals, "expected *leadership.tracker->*leadership.Tracker; got *leadership.tracker->*interface {}")
}