# File lib_ctrl/rucy/params.rb, line 407
    def save(properties)
      case (@params['stdout_logging_level'])
      when 'emerg', 'alert', 'crit', 'err', 'warning', 'notice', 'info', 'debug'
        # nothing to do.
      else
        raise "not allowed logging level: #{@params['stdout_logging_level'].inspect}"
      end

      for attrs in @params['logfiles']
        if (attrs['path'] == nil) then
          raise 'not allowed nil'
        end
        if (attrs['path'].strip.empty?) then
          raise 'not allowed empty string'
        end
        case (attrs['logging_level'])
        when 'emerg', 'alert', 'crit', 'err', 'warning', 'notice', 'info', 'debug'
          # nothing to do.
        else
          raise "not allowed logging level: #{attrs['logging_level'].inspect}"
        end
      end

      properties.set_params(@params)
      nil
    end