scale(inMin, inMax, outMin, outMax) {
    var scale = new Scale(inMin, inMax, outMin, outMax);
    var thisChain = this.mathOps.length;
    var nextChain = this.output;
    return p5.prototype._mathChain(this, scale, thisChain, nextChain, Scale);
  }
Scale this envelope's amplitude values to a given
 range, and return the envelope. Calling this method
 again will override the initial scale() with new values.

 @method  scale
 @for p5.Envelope
 @param  {Number} inMin  input range minumum
 @param  {Number} inMax  input range maximum
 @param  {Number} outMin input range minumum
 @param  {Number} outMax input range maximum
 @return {p5.Envelope} Envelope Returns this envelope
                                    with scaled output