docs: function(fields, data) {
      if (!_.isString(fields)) {
        return data;
      }
  
      // If a field is specified as `foo.bar` or `foo.bar.baz`,
      // Convert it to just `foo`
      var map = {};
      _.forEach(fields.split(','), function(field) {
        map[field.split('.')[0]] = 1;
      });
  
      var keys = _.keys(map);
      if (_.isArray(data)) {
        data = _.map(data, function(object) {
          return _.pick(object, keys);
        });
      } else if (_.isObject(data)) {
        data = _.pick(data, keys);
      }
  
      return data;
    }