set(attack, knee, ratio, threshold, release) {
    if (typeof attack !== 'undefined') {
      this.attack(attack);
    }
    if (typeof knee !== 'undefined') {
      this.knee(knee);
    }
    if (typeof ratio !== 'undefined') {
      this.ratio(ratio);
    }
    if (typeof threshold !== 'undefined') {
      this.threshold(threshold);
    }
    if (typeof release !== 'undefined') {
      this.release(release);
    }
  }
Set the paramters of a compressor.
@method  set
@for p5.Compressor
@param {Number} attack     The amount of time (in seconds) to reduce the gain by 10dB,
                           default = .003, range 0 - 1
@param {Number} knee       A decibel value representing the range above the
                           threshold where the curve smoothly transitions to the "ratio" portion.
                           default = 30, range 0 - 40
@param {Number} ratio      The amount of dB change in input for a 1 dB change in output
                           default = 12, range 1 - 20
@param {Number} threshold  The decibel value above which the compression will start taking effect
                           default = -24, range -100 - 0
@param {Number} release    The amount of time (in seconds) to increase the gain by 10dB
                           default = .25, range 0 - 1