public Accumulator[] rank(String qid, JSONObject query, int queryLength) {
GlobalEvidence globalEvidence = new GlobalEvidence(env.getDocumentCount(), env.getCollectionSize(), queryLength);
PostingsReaderWrapper structureReader;
ScoringFunction scoringFunction = new BM25ScoringFunction();
try {
structureReader = new PostingsReaderWrapper(query, env, scoringFunction, globalEvidence);
} catch (JSONException e) {
e.printStackTrace();
throw new RuntimeException(e);