code: public static MutableDoubleTuple standardDeviationFromVariance(
          DoubleTuple variance, MutableDoubleTuple result)
      {
          return DoubleTupleFunctions.apply(
              variance, Math::sqrt, result);
      }
docs: Returns the standard deviation of the given variances (that is,
  a tuple containing the square roots of the values in the given
  tuple).
  
  @param variance The input tuple
  @param result The result tuple
  @return The standard deviation
  @throws IllegalArgumentException If the given tuples do not have the
  same size