package packer type TestArtifact struct { id string destroyCalled bool } func (*TestArtifact) BuilderId() string { return "bid" } func (*TestArtifact) Files() []string { return []string{"a", "b"} } func (a *TestArtifact) Id() string { id := a.id if id == "" { id = "id" } return id } func (*TestArtifact) String() string { return "string" } func (a *TestArtifact) Destroy() error { a.destroyCalled = true return nil }