function TriOsc(freq) {
    oscillator_classCallCheck(this, TriOsc);
    return _super2.call(this, freq, 'triangle');
  }
Constructor: <code>new p5.TriOsc()</code>.
 This creates a Triangle Wave Oscillator and is
 equivalent to <code>new p5.Oscillator('triangle')
 </code> or creating a p5.Oscillator and then calling
 its method <code>setType('triangle')</code>.
 See p5.Oscillator for methods.

 @class  p5.TriOsc
 @constructor
 @extends p5.Oscillator
 @param {Number} [freq] Set the frequency