docs: public void setShrink(double shrink)
      {
          if(shrink >= 1 || shrink <= 0 || Double.isNaN(shrink) || Double.isInfinite(shrink) )
              throw new ArithmeticException("Shrinkage constant must be > 0 and < 1, not " + shrink);
          this.shrink = shrink;
      }