type fakeBackend … func (f *fakeBackend) ProcessEvents(events ...*auditinternal.Event) bool { … } func (f *fakeBackend) Run(stopCh <-chan struct{ … } func (f *fakeBackend) Shutdown() { … } func (f *fakeBackend) String() string { … } func TestUnion(t *testing.T) { … } type cannotMultipleRunBackend … func (b *cannotMultipleRunBackend) ProcessEvents(events ...*auditinternal.Event) bool { … } func (b *cannotMultipleRunBackend) Run(stopCh <-chan struct{ … } func (b *cannotMultipleRunBackend) Shutdown() { … } func (b *cannotMultipleRunBackend) String() string { … } func TestUnionRun(t *testing.T) { … }