protected class AbstractTreebankParserParams.SubcategoryStripper
The job of this class is to remove subcategorizations from
tag and category nodes, so as to put a tree in a suitable
state for evaluation. Providing the TreebankLanguagePack
is defined correctly, this should work for any language.
Does whatever one needs to do to a particular tree.
This routine is passed a whole Tree, and could itself
work recursively, but the canonical usage is to invoke this method
via the Tree.transform() method, which will apply the
transformer in a bottom-up manner to each local Tree,
and hence the implementation of TreeTransformer should
merely examine and change a local (one-level) Tree.