code: function LGAudioMediaSource() {
          this.properties = {
              gain: 0.5
          };
  
          this._audionodes = [];
          this._media_stream = null;
  
          this.addOutput("out", "audio");
          this.addInput("gain", "number");
  
          //create gain node to control volume
          var context = LGAudio.getAudioContext();
          this.audionode = context.createGain();
          this.audionode.graphnode = this;
          this.audionode.gain.value = this.properties.gain;
      }
docs: ****************************************************