def update_meta_data(trk, get_bounds = true)
      @lowest_point = trk.lowest_point if @lowest_point.nil? || (!trk.lowest_point.nil? && (trk.lowest_point.elevation < @lowest_point.elevation))
      @highest_point = trk.highest_point if @highest_point.nil? || (!trk.highest_point.nil? && (trk.highest_point.elevation > @highest_point.elevation))
      @bounds.add(trk.bounds) if get_bounds
      @distance += trk.distance
      @moving_duration += trk.moving_duration
    end
def update_meta_data(trk, get_bounds = true)
      @lowest_point = trk.lowest_point if @lowest_point.nil? || (!trk.lowest_point.nil? && (trk.lowest_point.elevation < @lowest_point.elevation))
      @highest_point = trk.highest_point if @highest_point.nil? || (!trk.highest_point.nil? && (trk.highest_point.elevation > @highest_point.elevation))
      @bounds.add(trk.bounds) if get_bounds
      @distance += trk.distance
      @moving_duration += trk.moving_duration
    end
Updates the meta data for this GPX file.  Meta data includes the
 bounds, the high and low points, and the distance.  This is useful when
 you modify the GPX data (i.e. by adding or deleting points) and you
 want the meta data to accurately reflect the new data.