op.prepare(mbx, res, mbidx, chunkSize);
op.prepare(mbx, res, mbidx, params, chunkSize);
    protected void prepare(Mailbox mbx, ZimbraQueryResultsImpl res,                MailboxIndex mbidx, int chunkSize) throws ServiceException, IOException {        // scale up the chunk size since we are doing an intersection...        chunkSize = (chunkSize+1) * 3;        mMessageGrouper = new HitGrouper[mQueryOperations.size()];        this.setupResults(mbx, res);        for (int i = 0; i < mQueryOperations.size(); i++) {            QueryOperation op = (QueryOperation) mQueryOperations.get(i);            op.prepare(mbx, res, mbidx, chunkSize);            mMessageGrouper[i] = new HitGrouper(op, res.getSortBy());            if (!op.hasNext()) {                //                // This operation has no terms at all. Since we're an                // Intersection query, that means that                // this entire query has no results. Sooo, lets release all of                // the operations we've already                // prepare()d and create a single operation, a                // NullQueryOperation below us.                //                if (mLog.isDebugEnabled()) {                    mLog.debug("*Dropping out of intersect query since we got to 0 results on execution "                                + Integer.toString(i + 1)                                + " out of "                                + mQueryOperations.size());                }                // first, we need to be DONE with all unused query operations..                for (int j = 0; j <= i; j++) {                    ((QueryOperation) mQueryOperations.get(j))                    .doneWithSearchResults();                }                mQueryOperations.clear();                mMessageGrouper = new HitGrouper[1];                QueryOperation nullOp = new NullQueryOperation();                addQueryOp(nullOp);                mMessageGrouper[0] = new HitGrouper(nullOp, res                            .getSortBy());                return;            }        }    }