docs: @Override
  	public double integrate(DoubleUnaryOperator integrand) {
  
  		// We use commons-math RombergIntegrator
  		return new RombergIntegrator().integrate(numberOfEvaluationPoints, new UnivariateFunction() {
  			@Override
  			public double value(double argument) {
  				return integrand.applyAsDouble(argument);
  			}
  		}, getLowerBound(), getUpperBound());
  	}