setLoop(bool) {
    if (bool === true) {
      this._looping = true;
    } else if (bool === false) {
      this._looping = false;
    } else {
      throw 'Error: setLoop accepts either true or false';
    }
    if (this.bufferSourceNode) {
      this.bufferSourceNode.loop = this._looping;
      this._counterNode.loop = this._looping;
    }
  }
Set a p5.SoundFile's looping flag to true or false. If the sound
is currently playing, this change will take effect when it
reaches the end of the current playback.

@method setLoop
@for p5.SoundFile
@param {Boolean} Boolean   set looping to true or false