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
  }
}