reverseBuffer() {
    if (this.buffer) {
      var currentPos = this._lastPos / ac.sampleRate;
      var curVol = this.getVolume();
      this.setVolume(0, 0.001);

      const numChannels = this.buffer.numberOfChannels;
      for (var i = 0; i < numChannels; i++) {
        this.buffer.getChannelData(i).reverse();
      }
      // set reversed flag
      this.reversed = !this.reversed;

      if (this.isPlaying() && currentPos) {
        this.jump(this.duration() - currentPos);
      }
      this.setVolume(curVol, 0.001);
    } else {
      throw 'SoundFile is not done loading';
    }
  }
Reverses the p5.SoundFile's buffer source.
 Playback must be handled separately (see example).

 @method  reverseBuffer
 @for p5.SoundFile
 @example
 <div><code>
 let drum;
 function preload() {
   drum = loadSound('assets/drum.mp3');
 }

 function setup() {
   let cnv = createCanvas(100, 100);
   cnv.mousePressed(canvasPressed);
   background(220);
   text('tap to play', 20, 20);
 }

 function canvasPressed() {
   drum.stop();
   drum.reverseBuffer();
   drum.play();
 }
</code>
</div>