docs: protected void doAddValue( T value ) {
          if (value == null) return;
          // Modify the basic statistics ...
          ++this.count;
          this.total = math.add(this.total, value);
          this.maximum = this.math.maximum(this.maximum, value);
          this.minimum = this.math.minimum(this.minimum, value);
          // Calculate the mean and standard deviation ...
          int count = getCount();
          if (count == 1) {
              // M(1) = x(1)
              this.meanValue = value.doubleValue();
              this.mean = value;
          } else {
              double dValue = value.doubleValue();
              double dCount = count;
              // M(k) = M(k-1) + ( x(k) - M(k-1) ) / k
              this.meanValue = this.meanValue + ((dValue - this.meanValue) / dCount);
              this.mean = this.math.create(this.meanValue);
          }
      }