GPS clock_info - a few questions

Thanks for that, that worked.

I have been testing the next iteration.
I have noticed that after I have hada fix that after swiping out of the clock_info back to say the battery display that the GPS gets powered on again.

My question is:

  var timeout;   // is this the same variable as

        hide: function() {
          Bangle.setGPSPower(0,"clkinfo");
          Bangle.removeListener("GPS", onGPS);
          if (this.timeout) {
            clearTimeout(this.timeout);  /// <<<<  as the variable here ?
            this.timeout = undefined;
          }
          resetLastFix();
        }

I'm not 100% sure I understand how this.timeout gets defined in code at:

https://github.com/espruino/BangleApps/blob/master/apps/clock_info/lib.js
line 83

      hide : function() {
        Bangle.setHRMPower(0,"clkinfo");
        Bangle.removeListener("HRM", hrmUpdateHandler);
        if (this.timeout) {
          clearTimeout(this.timeout);
          this.timeout = undefined;   //////  where does timeout get declared, just seems to spring into existance
        }
        hrm = 0;
      },
    }