function FOAConvolver(context, hrirBufferList) {
  this._context = context;

  this._active = false;
  this._isBufferLoaded = false;

  this._buildAudioGraph();

  if (hrirBufferList) {
    this.setHRIRBufferList(hrirBufferList);
  }

  this.enable();
}
FOAConvolver. A collection of 2 stereo convolvers for 4-channel FOA stream.
@constructor
@param {BaseAudioContext} context The associated AudioContext.
@param {AudioBuffer[]} [hrirBufferList] - An ordered-list of stereo
AudioBuffers for convolution. (i.e. 2 stereo AudioBuffers for FOA)