// [START update_entity]
// MarkDone marks the task done with the given ID.
func MarkDone(ctx context.Context, client *datastore.Client, taskID int64) error {
// Create a key using the given integer ID.
key := datastore.IDKey("Task", taskID, nil)
// In a transaction load each task, set done to true and store.
_, err := client.RunInTransaction(ctx, func(tx *datastore.Transaction) error {
var task Task
if err := tx.Get(key, &task); err != nil {
return err
}
task.Done = true
_, err := tx.Put(key, &task)
return err
})
return err
}
