anchor.diff:      Map m = {
         "Format": "RSfxr",
         "Name": name,
  +      "Gain": _mixer.gain.value,
         "Channels": chans
       };
       
       return m;
     }
  +  
  +  double toDouble(Object o) {
  +    if (o == null)
  +      return 0.0;
  +    num d = o as num;
  +    return d.toDouble();
  +  }
  +
   }
positive.code:       wa.output.connectNode(_mixer);
      }
  
      _mixer.gain.value = 1.0 - ((chans.length - 1) / 10.0);
  
      selectChannel(0);
    }
  
negative.code:       WASfxr effect = _effects[index];
        effect.enabled = enabled;
        
        // Does not work as expected. DISABLED for now.
        // The GainNode is additive so we scale by the total effects active.
        //int chans = enabledChannels;
        //if (chans > 0)
        //  _mixer.gain.value = _baseGain - ((chans - 1) / 10.0);
        //else
        //  _mixer.gain.value = _baseGain;
        
        trigger();
        return;
  