This patch does two things:
* Add strict PHP 7 type hints to most code.
* Narrow the interface of the checkRefsNoReferences() method to not
require a ParserOptions object any more.
Change-Id: I91c6a2d9b76915d7677a3f735ee8e054c898fcc5
There was a call in the API that was *not* using normalizeKey(). Now
that the API is gone, we can inline this.
This patch also contains a bunch of cleanups that might already been
resolved in the previous patches.
Change-Id: Id3767b5830268c8cfe9c10efabfa4a31e9dafeb8
