簡單的 Scaladoc 方法
/**
* Explain briefly what method does here
* @param x Explain briefly what should be x and how this affects the method.
* @param y Explain briefly what should be y and how this affects the method.
* @return Explain what is returned from execution.
*/
def method(x: Int, y: String): Option[Double] = {
// Method content
}