The move to the use of generic PostingIndex structures for the Direct and Inverted indices causes errors in the DependenceScoreModifier.openPostingLists() method, since the POINTERTYPE or index.getInvertedIndex().getPostings() is not known a priori. The assumption that DependenceScoreModifier.openPostingLists() makes is that POINTERTYPE is LexconEntry or extends LexconEntry, e.g. MemoryLexiconEntry. However, getInvertedIndex() returns a PostingIndex<Pointer>, i.e. is more generic.
Since when an index calls PostingIndex.getPostings() POINTERTYPE is generic (type Pointer), the method should only type check for '? extends Pointer' rather than 'is POINTERTYPE that extends Pointer'.