connect(unit) {
    if (unit) {
      if (unit.hasOwnProperty('input')) {
        this.output.connect(unit.input);
      } else if (unit.hasOwnProperty('analyser')) {
        this.output.connect(unit.analyser);
      } else {
        this.output.connect(unit);
      }
    } else {
      this.output.connect(p5sound.input);
    }
    if (unit && unit._onNewInput) {
      unit._onNewInput(this);
    }
  }
Connect to an audio unit. If no parameter is provided, will
 connect to the main output (i.e. your speakers).<br/>

 @method  connect
 @for p5.AudioIn
 @param  {Object} [unit] An object that accepts audio input,
                         such as an FFT