It was deprecated before me, I would be happy marking the API as "internal" or something. Point is these methods are for the FunctionFinder to  call to set up an instance. I did fix up the javadocs to make the workflow sane.

There has been some confusion about the workflow associated with these methods: example the Env function was trying to ignore Fallback value. Trouble is Fallback is for the SLD data structure, to be used by systems that do not have an implementation of Env function ...