docs: @Override
  	public RandomVariable addProduct(RandomVariable factor1, RandomVariable factor2) {
  		return apply(new DoubleBinaryOperator() {
  			@Override
  			public double applyAsDouble(double x, double y) {
  				return x + y;
  			}
  		}, new DoubleBinaryOperator() {
  			@Override
  			public double applyAsDouble(double x, double y) {
  				return x * y;
  			}
  		}, factor1, factor2);
  	}