code: private String generateQueryId(QueryInfo queryInfo) {
  		String queryId = SPF.get().getUniqueIdentifier() + (++id);
  		queryInfo.setQueryId(queryId);
  		return queryId;
  	}
docs: Generate a query id for the specified query. The query id is assigned to
  the query descriptor.
  
  @param queryInfo
  @return the query id