code: public void setLearningRate(double learningRate)
      {
          if(Double.isInfinite(learningRate) || Double.isNaN(learningRate) || learningRate <= 0)
              throw new IllegalArgumentException("Learning rate must be positive, not " + learningRate);
          this.learningRate = learningRate;
      }
docs: Sets the learning rate to use
  @param learningRate the learning rate &gt; 0.