docs: synchronized void addDataPoint(double value, int updated) {
          // 8/10/2012: Force the standard deviation to 1/3 of the first data point
          // 8/11:2012: Force it to 1/6th of the first data point (more accurate)
          if (ewmaVariance == Double.NEGATIVE_INFINITY) {
              reset(value, updated);
              return;
          }
  
          double delta = value - ewma;
          double increment = ALPHA * delta;
  
          ewma += increment;
          ewmaVariance = (1 - ALPHA) * (ewmaVariance + delta * increment);
          ewmaStddev = Math.sqrt(ewmaVariance);
  
          lastUpdate = updated;
      }