return nextIndex >= 0;
    }

    /**
     * Checks whether nextIndex is valid; if so setting nextItem. Stops iterator when either hits
     * putIndex or sees null item.
     */
    private void checkNext() {
      if (nextIndex == putIndex) {
        nextIndex = -1;
        nextItem = null;
      } else {
        nextItem = items[nextIndex];
        if (nextItem == null) nextIndex = -1;
      }
    }

		}

		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",

		// user pet
		if users2[idx].NamedPet == nil {
			t.Fatalf("Failed to load NamedPet")
		}
		CheckPet(t, *user.NamedPet, *users2[idx].NamedPet)
		// manager pet
		if users2[idx].Manager.NamedPet == nil {
			t.Fatalf("Failed to load NamedPet")
		}
		CheckPet(t, *user.Manager.NamedPet, *users2[idx].Manager.NamedPet)
	}
}

func TestJoinsPreload_Issue7013(t *testing.T) {

		// user pet
		if users2[idx].NamedPet == nil {
			t.Fatalf("Failed to load NamedPet")
		}
		CheckPet(t, *user.NamedPet, *users2[idx].NamedPet)
		// manager pet
		if users2[idx].Manager.NamedPet == nil {
			t.Fatalf("Failed to load NamedPet")
		}
		CheckPet(t, *user.Manager.NamedPet, *users2[idx].Manager.NamedPet)
	}
}

func TestGenericsPreloads(t *testing.T) {

		return errors.New("public key authority validation requested but no ca public key specified.")
	}

	cert, ok := clientKey.(*ssh.Certificate)
	if !ok {
		return errSftpPublicKeyWithoutCert
	}

	// ssh.CheckCert called by ssh.Authenticate accepts certificates
	// with empty principles list so we block those in here.
	if len(cert.ValidPrincipals) == 0 {
		return errSftpCertWithoutPrincipals
	}