Yuyang

Created PR #238 for fixing the reduced depth issue. Not sure if the `UnknownType` node should also be pushed to `this.context` (omitted in PR) FYI, a smaller code snippet that...

I am a novice user of Javaparser, but if I understood correctly, it is normal for `UnknownType` to have null range. Class hierarchy of `UnknownType`: `UnknownType`⇾`Type`⇾`Node`⇢`NodeWithRange` [The Javadoc in `Range`](https://github.com/javaparser/javaparser/blob/b00ae190d22d2f99f15ff5e3fa8898055c1b877d/javaparser-core/src/main/java/com/github/javaparser/Range.java#L26-L59)...

I agree, a node with no lexical representation is not of interest for an AST differencing tool.

(Probably more appropriate to be discussed in a separate issue) I am wondering why we have the ` + 2;` here. In SwingDiff the highlighted area seems to be one...

>Do you want to try a PR ? The PR #238 has already been created :)