docs: public void setErrorTolerance(double errorTolerance)
      {
          if(Double.isNaN(errorTolerance) || errorTolerance < 0 || errorTolerance > 1)
              throw new IllegalArgumentException("Error tolerance must be in [0, 1], not " + errorTolerance);
          this.errorTolerance = errorTolerance;
          for(KernelPoint kp : points)
              kp.setErrorTolerance(errorTolerance);
      }