ents, l = a.length, ax;
  while (l && this.length) {
    what = a[--l];
    while ((ax = this.indexOf(what)) != -1) {
      this.splice(ax, 1);
    }
  }
  return this;
}

/**
 * Displays a new chart.
 *
 * @param {Number} hz Number of sample per second of the data.
 * @param {String} name Name to display on top of chart.
 * @param {Number[][]} values Array of value arrays to display.
 * @param {Boolean} stacked Whether to display values as stacked.
 */
function displayChart(hz, name, values, units, stacked