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

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