return {
  init = function()
    local loader = nil
    packer_plugins = packer_plugins or nil -- suppress warnings
    local log = require('navigator.util').log
    -- packer only
    if packer_plugins ~= nil then -- packer install
      local lazy_plugins = {
        ['nvim-lspconfig'] = 'neovim/nvim-lspconfig',
        ['guihua.lua'] = 'ray-x/guihua.lua',
      }

      if _NgConfigValues.lsp_installer == true then
        lazy_plugins['nvim-lsp-installer'] = 'williamboman/nvim-lsp-installer'
      end

      -- packer installed
      loader = require('packer').loader
      for plugin, url in pairs(lazy_plugins) do
        if not packer_plugins[url] or not packer_plugins[url].loaded then
          -- log("loading ", plugin)
          loader(plugin)
        end
      end
    else
      loader = function(plugin)
        local cmd = 'packadd ' .. plugin
        vim.cmd(cmd)
      end
    end

    if _NgConfigValues.lsp_installer == true then
      vim.cmd('packadd nvim-lsp-installer')
      local has_lspinst, lspinst = pcall(require, 'nvim-lsp-installer')
      log('lsp_installer installed', has_lspinst)
      if has_lspinst then
        lspinst.setup()
        local configs = require('lspconfig/configs')
        local servers = require('nvim-lsp-installer').get_installed_servers()
        for _, server in pairs(servers) do
          local cfg = require('navigator.lspclient.clients').get_cfg(server)
          local lsp_inst_cfg = configs[server]
          if lsp_inst_cfg and lsp_inst_cfg.document_config.default_config then
            lsp_inst_cfg = lsp_inst_cfg.document_config.default_config
            lsp_inst_cfg = vim.tbl_deep_extend('keep', lsp_inst_cfg, cfg)
            require('lspconfig')[server].setup(lsp_inst_cfg)
          end
        end
      end
    end
  end,
  load = function(plugin_name, path)
    local loader = nil
    packer_plugins = packer_plugins or nil -- suppress warnings
    -- packer only
    if packer_plugins ~= nil then -- packer install
      local lazy_plugins = {}
      lazy_plugins[plugin_name] = path
      loader = require('packer').loader
      for plugin, _ in pairs(lazy_plugins) do
        if packer_plugins[plugin] and packer_plugins[plugin].loaded == false then
          -- log("loading ", plugin)
          pcall(loader, plugin)
        end
      end
    end
  end,
}