&Pet{Name: "pet-slice-append-1"},
		[]*Pet{{Name: "pet-slice-append-2-1"}, {Name: "pet-slice-append-2-2"}},
		&Pet{Name: "pet-slice-append-3"},
	)

	AssertAssociationCount(t, users, "Pets", 10, "After Append")

	// Replace -> same as append
	DB.Model(&users).Association("Pets").Replace(
		[]*Pet{{Name: "pet-slice-replace-1-1"}, {Name: "pet-slice-replace-1-2"}},

		}

		if err := DB.Create(&pet).Error; err != nil {
			t.Fatalf("errors happened when create: %v", err)
		}

		CheckPet(t, pet, pet)

		var pet2 Pet
		DB.Preload("Toy").Find(&pet2, "id = ?", pet.ID)
		CheckPet(t, pet2, pet)
	})

	t.Run("Slice", func(t *testing.T) {
		pets := []Pet{{
			Name: "PolymorphicHasOne-Slice-1",
			Toy:  Toy{Name: "Toy-PolymorphicHasOne-Slice-1"},
		}, {

		t.Fatalf("load u2: %v", err)
	}
	if len(got1.Pets) != 1 || got1.Pets[0].Name != "x" {
		t.Fatalf("u1 pet not updated: %+v", got1.Pets)
	}
	if len(got2.Pets) != 1 || got2.Pets[0].Name != "x" {
		t.Fatalf("u2 pet not updated: %+v", got2.Pets)
	}

	del := clause.Association{Association: "Pets", Type: clause.OpDelete}

	} else {
		sort.Slice(users2[2].Pets, func(i, j int) bool {
			return users2[2].Pets[i].ID < users2[2].Pets[j].ID
		})

		for _, pet := range users2[2].Pets[0:2] {
			if pet.Toy.Name != "" {
				t.Errorf("No toy should for user %v's pet %v but got %v", 3, pet.Name, pet.Toy.Name)
			}
		}

		CheckPet(t, *users2[2].Pets[2], *users[2].Pets[2])
	}
}

func TestPreloadEmptyData(t *testing.T) {

	DB.Joins("inner join pets on pets.user_id = users.id AND pets.name = @Name", user.Pets[0]).Where("users.name = ?", user.Name).First(&users6)
	if len(users6) != 1 {
		t.Errorf("should find one users using left join with conditions, but got %v", len(users6))
	}

	dryDB := DB.Session(&gorm.Session{DryRun: true})

			}
		} else if len(result.Pets) != 5 {
			t.Fatalf("Preload user %v pets should be 5, but got %+v", result.Name, result.Pets)
		}
		for i := 1; i < len(result.Pets); i++ {
			if result.Pets[i-1].Name < result.Pets[i].Name {
				t.Fatalf("Preload user %v pets not ordered correctly, last %v, cur %v", result.Name, result.Pets[i-1], result.Pets[i])
			}
		}
	}

	}

	r = dryDB.Table("(?) as u, (?) as p", DB.Model(&User{}).Select("name"), DB.Model(&Pet{}).Select("name")).Find(&User{}).Statement
	if !regexp.MustCompile("SELECT \\* FROM \\(SELECT .name. FROM .users. WHERE .users.\\..deleted_at. IS NULL\\) as u, \\(SELECT .name. FROM .pets. WHERE .pets.\\..deleted_at. IS NULL\\) as p WHERE .u.\\..deleted_at. IS NULL").MatchString(r.Statement.SQL.String()) {

			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",

	result.Pets = append(user.Pets, result.Pets...)
	result.Team = append(user.Team, result.Team...)
	result.Friends = append(user.Friends, result.Friends...)

	sort.Slice(result.Pets, func(i, j int) bool {
		return result.Pets[i].ID < result.Pets[j].ID
	})

    Set<Integer> set2 = newHashSet(2, 3);
    Set<Integer> difference = difference(set1, set2);
    assertThat(difference).containsExactly(1);
    set1.add(0);
    assertThat(difference).containsExactly(0, 1);
    set2.remove(2);
    assertThat(difference).containsExactly(0, 1, 2);
  }

  public void testSymmetricDifference_isView() {
    Set<Integer> set1 = newHashSet(1, 2);