func TestCallbacksRemove(t *testing.T) {
	db, _ := gorm.Open(nil, nil)
	createCallback := db.Callback().Create()

	createCallback.Before("*").Register("c1", c1)
	createCallback.After("*").Register("c2", c2)
	createCallback.Before("c4").Register("c3", c3)
	createCallback.After("c2").Register("c4", c4)

	// callbacks: []string{"c1", "c3", "c4", "c2"}
	createCallback.Remove("c1")