code: function req (name, opts) {
    if (opts && opts.require) {
      return opts.require(name, opts)
    }
    var fp = require.resolve(name)
    return require(fp)
  }
docs: Default `require` function. Pass a custom function to
  `opts.require` to override.
  
  @param  {String} `name`
  @param  {Object} `opts`
  @return {String}