return {
    {
        "mbbill/undotree",
        keys = {
            { "<leader>u", "<cmd>UndotreeToggle<cr>", desc = "toggle undotree" },
        },
        config = function()
            vim.g.undotree_WindowLayout = 4
            vim.g.undotree_SplitWidth = 40
            vim.g.undotree_SetFocusWhenToggle = 1
        end
    }
}