The getLinkIfPresent method deals with a difference between RSS and Atom: In RSS, the node value is the actual link, while in Atom you need to use the href attribute.
getLinkIfPresent 方法则可处理 RSS 和 Atom 之间的差异：在 RSS 中，节点值就是实际的链接，而在 Atom 中，则需要使用 href 属性。
2
The method assert compares an expected value to an actual value for the particular test scenario.
这个方法assert在这个特殊的测试情景下，将期望值与实际值进行了对比。
3
The purpose to develop this software package, the method to realize its functions, the actual effect and the value to popularize it are introduced in this article.