class DoubleRangeLimitTransform implements ParameterLimitsTransform {

  @Override
  public double transformGradient(final double x) {
    Validate.isTrue(x <= _upper && x >= _lower, "parameter out of range");
    final double t = (x - _mid) / _scale;
    return 1 / (_scale * (1 - t * t));
  }

  public  DoubleRangeLimitTransform(final double lower, final double upper);

}