UnityEditor.GameObjectTreeViewDataSource.GetParentsAbove C# (CSharp) Method

        protected override HashSet<int> GetParentsAbove(int id)
        {
            HashSet<int> set = new HashSet<int>();
            IHierarchyProperty property = new HierarchyProperty(HierarchyType.GameObjects);
            if (property.Find(id, null))
            {
                while (property.Parent())
                {
                    set.Add(property.instanceID);
                }
            }
            return set;
        }