code: function(allowedAttributes) {
      var self = this.chain()
  
      self.setInternal('as_json', true)
  
      if (Array.isArray(allowedAttributes))
        self.setInternal('allowed_attributes', allowedAttributes)
  
      return self
    }
docs: `exec()` will return raw JSON instead of records
  @class Model
  @method asJson
  @param {array} allowed_attributes - Optional: Only export the given attributes and/or relations
  
  @return {Model}
  @see Model.exec()