return {
  "nvim-tree/nvim-tree.lua",
  dependencies = {
    'kyazdani42/nvim-web-devicons'
  },
  keys = {
    "<c-e>"
  },
  config = function()
    require 'nvim-web-devicons'.setup {}

    require 'nvim-tree'.setup {
      sort_by   = "case_sensitive",
      view      = {
        width = 30,
      },
      filters   = { dotfiles = true, },
      git       = { enable = true },
      on_attach = function(bufnr)
        local api = require 'nvim-tree.api'
        api.config.mappings.default_on_attach(bufnr)

        -- override a default
        G.map({
          { 'n', 'v', api.node.open.vertical,   { buffer = bufnr } },
          { 'n', 's', api.node.open.horizontal, { buffer = bufnr } },
        })

        G.delmap({
          { 'n', '<C-e>', { buffer = bufnr } },
          { 'n', '<C-v>', { buffer = bufnr } },
          { 'n', '<C-x>', { buffer = bufnr } },
        })
      end
    }
    G.map({
      { "n", "<C-e>", ":NvimTreeToggle<CR>", { noremap = true } },
    })
  end
}