code: function FileWriter (path, opts) {
    if (!(this instanceof FileWriter)) return new FileWriter(path, opts);
    Writer.call(this, opts);
    this.path = path;
    this.file = fs.createWriteStream(path, opts);
    this.pipe(this.file);
    this.on('header', this._onHeader);
  }
docs: The `FileWriter` class.
  
  @param {String} path The file path to write the WAVE file to
  @param {Object} opts Object contains options for the stream and format info
  @api public