UnityEditor.GameObjectTreeViewDataSource.GetParentsBelow C# (CSharp) Method

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