ta point
   * @param value the value of this data point
   * @param sumRepeatedTimeStampValues if <code>timestamp</code> has an exact match in the series, this flag controls
   * whether it is replaced, or the values summed (defaults to false.)
   */
  TimeSeries.prototype.append = function(timestamp, value, sumRepeatedTimeStampValues) {
    // Rewind until we hit an older timestamp
    var i = this.data.length - 1;
    while (i >= 0 && this.data[i][0] > timestamp) {
      i--;
    }

    if (i === -1) {
  