code: private DBObject generateFilterQuery(MongoPartition partition) {
  
          if (mongoDeepJobConfig.getQuery() != null) {
              QueryBuilder queryBuilder = QueryBuilder.start();
  
              queryBuilder.and(createQueryPartition(partition), mongoDeepJobConfig.getQuery());
  
              LOG.debug("mongodb query "+queryBuilder.get());
  
              return queryBuilder.get();
          }
  
          return createQueryPartition(partition);
  
      }
docs: Generate filter query.
  
  @param partition the partition
  @return the dB object