code: public void setEps(double eps)
      {
          if(Double.isNaN(eps) || eps < 0 || Double.isInfinite(eps))
              throw new IllegalArgumentException("eps must be non-negative, not "+eps);
          this.eps = eps;
      }
docs: Sets the {@code eps} used in the epsilon insensitive loss function used
  when performing regression. Errors in the output that less than
  {@code eps} during training are treated as correct.
  <br>
  This parameter has no impact on classification problems.
  
  @param eps the non-negative value to use as the error tolerance in regression