anchor.diff:  
       pollingInterval = mkOption {
         type = types.int;
  -      default = 7;
  +      default = 1;
         description = ''
           The polling interval.
         '';
  
positive.code: 
      highTemp = mkOption {
        type = types.int;
        default = 66;
        description = ''
          The high temperature.
        '';
  
negative.code:     environment = {
        etc."mbpfan.conf".text = ''
          [general]
          min_fan1_speed = ${toString cfg.minFanSpeed}
          max_fan1_speed = ${toString cfg.maxFanSpeed}
          low_temp = ${toString cfg.lowTemp}
          high_temp = ${toString cfg.highTemp}
          max_temp = ${toString cfg.maxTemp}
  