/**
  * Create an analytic swaption approximation product for log normal forward rate model.
  *
  * <p>Note: It is implicitly assumed that swapTenor.getTime(0) is the exercise date (no forward
  * starting).
  *
  * @param swaprate The strike swap rate of the swaption.
  * @param swapTenor The swap tenor in doubles.
  */
 public SwaptionAnalyticApproximation(double swaprate, TimeDiscretizationInterface swapTenor) {
   this(swaprate, swapTenor.getAsDoubleArray(), ValueUnit.VALUE);
 }