code: function calculateAvailability(timeColumn, index, endTime) {
    var startJulianDate = timeColumn.julianDates[index];
    if (defined(startJulianDate)) {
      var finishJulianDate = finishFromIndex(timeColumn, index);
      return new TimeInterval({
        start: timeColumn.julianDates[index],
        stop: finishJulianDate,
        isStopIncluded: JulianDate.equals(finishJulianDate, endTime),
        data: timeColumn.julianDates[index] // Stop overlapping intervals being collapsed into one interval unless they start at the same time
      });
    }
  }
docs: Calculate and return the availability interval for the index'th entry in timeColumn.
  If the entry has no valid time, returns undefined.
  @private
  @param  {TableColumn} timeColumn The time column that applies to this data.
  @param  {Integer} index The index into the time column.
  @param  {JulianDate} endTime The last time for all intervals.
  @return {TimeInterval} The time interval over which this entry is visible.