why it's still to do [do merge sort for prevent memory exceed](https://github.com/nvim-tree/nvim-tree.lua/blob/master/lua/nvim-tree/explorer/sorter.lua#L144-L162) when the configation of `sort.sorter` [does return nothing](https://github.com/nvim-tree/nvim-tree.lua/blob/master/lua/nvim-tree/explorer/sorter.lua#L137) since the nodes in the variable `t_users` is in the order defined by the user, maybe it's better not to do that? Best wishes!