IfcDoc.FormEdit.UpdateTreeDeletionNode C# (CSharp) Method

        private void UpdateTreeDeletionNode(TreeNodeCollection col)
        {
            bool recurse = true;
            for(int iNode = col.Count - 1; iNode >= 0; iNode--)
            {
                TreeNode tn = col[iNode];
                if (tn.Tag is SRecord)
                {
                    SRecord record = (SRecord)tn.Tag;
                    if (record.OID == -1)
                    {
                        tn.Remove();
                        recurse = false;
                    }
                }

                if (recurse)
                {
                    UpdateTreeDeletionNode(tn.Nodes);
                }
            }
        }