First line of implementation has missing or incorrect syntax highlighting

[avikrao]

As can be seen, for some reason, the first line after a definition (first line of implementation) sometimes lacks syntax highlighting, or has the wrong syntax highlighting

Another example:

In this example, the def keyword and string literal are missing syntax highlighting and the toInt method on the same line has it, but it is not the correct highlighting (method highlighting should be green, as exemplified by foldLeft on line 14.

[eed3si9n]

I think this was fixed in #62, but I just added highlighting test to make sure this won't regress - #142