UnityEditor.PackageExportTreeView.GetFolderChildrenEnabledState C# (CSharp) Method

        private EnabledState GetFolderChildrenEnabledState(PackageExportTreeViewItem folder)
        {
            if (!folder.isFolder)
            {
                Debug.LogError("Should be a folder item!");
            }
            if (!folder.hasChildren)
            {
                return EnabledState.None;
            }
            EnabledState notSet = EnabledState.NotSet;
            PackageExportTreeViewItem item = folder.children[0] as PackageExportTreeViewItem;
            EnabledState enabledState = item.enabledState;
            for (int i = 1; i < folder.children.Count; i++)
            {
                PackageExportTreeViewItem item2 = folder.children[i] as PackageExportTreeViewItem;
                if (enabledState != item2.enabledState)
                {
                    notSet = EnabledState.Mixed;
                    break;
                }
            }
            if (notSet == EnabledState.NotSet)
            {
                notSet = (enabledState != EnabledState.All) ? EnabledState.None : EnabledState.All;
            }
            return notSet;
        }