save(fileName) {
    p5.prototype.saveSound(this, fileName, 'wav');
  }
Save a p5.SoundFile as a .wav file. The browser will prompt the user
to download the file to their device. To upload a file to a server, see
<a href="/reference/#/p5.SoundFile/getBlob">getBlob</a>

@method save
@for p5.SoundFile
@param  {String} [fileName]      name of the resulting .wav file.
@example
 <div><code>
 let mySound;
 function preload() {
   mySound = loadSound('assets/doorbell.mp3');
 }
 function setup() {
   let cnv = createCanvas(100, 100);
   cnv.mousePressed(canvasPressed);
   background(220);
   text('tap to download', 10, 20);
 }

 function canvasPressed() {
   mySound.save('my cool filename');
 }
</code></div>