return ErrUnknownHandler
	}
	s := strings.Join(subroute, "/")
	if debugPrint {
		fmt.Println("RegisterSingleHandler: ", id.String(), "subroute:", s)
	}

	if len(subroute) == 0 {
		if m.handlers.hasAny(id) && !id.isTestHandler() {
			return fmt.Errorf("handler %v: %w", id.String(), ErrHandlerAlreadyExists)
		}

		m.handlers.single[id] = h
		return nil
	}
	subID := makeSubHandlerID(id, s)

func (h *handlers) init() {
	h.subSingle = make(map[subHandlerID]SingleHandlerFn)
	h.subStateless = make(map[subHandlerID]*StatelessHandler)
	h.subStreams = make(map[subHandlerID]*StreamHandler)
}

func (h *handlers) hasAny(id HandlerID) bool {
	if !id.valid() {
		return false
	}
	return h.single[id] != nil || h.stateless[id] != nil || h.streams[id] != nil
}

func (h *handlers) hasSubhandler(id subHandlerID) bool {

		case reflect.Struct:
			relation.Type = HasOne
		case reflect.Slice:
			relation.Type = HasMany
		}
	}

	if schema.err == nil {
		schema.setRelation(relation)
		switch relation.Type {
		case HasOne:
			schema.Relationships.HasOne = append(schema.Relationships.HasOne, relation)
		case HasMany:
			schema.Relationships.HasMany = append(schema.Relationships.HasMany, relation)
		case BelongsTo:

			}
			if association.Unscope && oldBelongsToExpr != nil {
				association.Error = association.DB.Model(nil).Where(oldBelongsToExpr).Delete(reflect.New(rel.FieldSchema.ModelType).Interface()).Error
			}
		case schema.HasOne, schema.HasMany:
			var (
				primaryFields []*schema.Field
				foreignKeys   []string
				updateMap     = map[string]interface{}{}

	relations := []Relation{
		{
			Name: "Account", Type: schema.HasOne, Schema: "User", FieldSchema: "Account",
			References: []Reference{{"ID", "User", "UserID", "Account", "", true}},
		},
		{
			Name: "Pets", Type: schema.HasMany, Schema: "User", FieldSchema: "Pet",
			References: []Reference{{"ID", "User", "UserID", "Pet", "", true}},
		},
		{
			Name: "Toys", Type: schema.HasMany, Schema: "User", FieldSchema: "Toy",

		t.Errorf("account's number should not be saved")
	}
}

func TestHasOneAssociationForSlice(t *testing.T) {
	users := []User{
		*GetUser("slice-hasone-1", Config{Account: true}),
		*GetUser("slice-hasone-2", Config{Account: false}),
		*GetUser("slice-hasone-3", Config{Account: true}),
	}

	DB.Create(&users)

	// Count
	AssertAssociationCount(t, users, "Account", 2, "")

	// Find

	}

	AssertAssociationCount(t, user2, "Team", 0, "after clear")
}

func TestHasManyAssociationForSlice(t *testing.T) {
	users := []User{
		*GetUser("slice-hasmany-1", Config{Pets: 2}),
		*GetUser("slice-hasmany-2", Config{Pets: 0}),
		*GetUser("slice-hasmany-3", Config{Pets: 4}),
	}

	DB.Create(&users)

	// Count
	AssertAssociationCount(t, users, "Pets", 6, "")

	// Find
	var pets []Pet

				return
			}

			writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
			return
		}

		hasEnv := false
		for _, ci := range cfgInfos {
			if ci.IsCfg && ci.IsEnv {
				hasEnv = true
				break
			}
		}

		if hasEnv {
			writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrAdminConfigEnvOverridden), r.URL)
			return
		}
	case madmin.LDAPIDPCfg:

		}
	}

	fieldValues := make([]interface{}, len(relForeignFields))

	// clean up old values before preloading
	switch reflectValue.Kind() {
	case reflect.Struct:
		switch rel.Type {
		case schema.HasMany, schema.Many2Many:
			tx.AddError(rel.Field.Set(tx.Statement.Context, reflectValue, reflect.MakeSlice(rel.Field.IndirectFieldType, 0, 10).Interface()))
		default: