def query_string
      params = {}

      self.query_params.each do |param|
        params[param.name] = param.value
      end

      return ::URI::QueryParams.dump(params)
    end
def query_string
      params = {}

      self.query_params.each do |param|
        params[param.name] = param.value
      end

      return ::URI::QueryParams.dump(params)
    end
Dumps the URL query params into a URI query string.

 @return [String]
   The URI query string.

 @since 1.0.0

 @api public