code: func (e *FwdEdge) Fwd(c context.Context) (*Attempt, *FwdDep) {
  	atmpt := &Attempt{ID: *e.From}
  	return atmpt, &FwdDep{
  		Depender: ds.KeyForObj(c, atmpt),
  		Dependee: *e.To,
  	}
  }
docs: // Fwd returns the Attempt (From) and FwdDep (To) models that this FwdEdge
  // represents.