code: @Deprecated
      @SuppressWarnings("unchecked")
      public AggregationOutput aggregate(final DBObject firstOp, final DBObject... additionalOps) {
          List<DBObject> pipeline = new ArrayList<DBObject>();
          pipeline.add(firstOp);
          Collections.addAll(pipeline, additionalOps);
          return aggregate(pipeline);
      }
docs: Method implements aggregation framework.
  
  @param firstOp       requisite first operation to be performed in the aggregation pipeline
  @param additionalOps additional operations to be performed in the aggregation pipeline
  @return the aggregation operation's result set
  @mongodb.driver.manual core/aggregation-pipeline/ Aggregation
  @mongodb.server.release 2.2
  @deprecated Use {@link #aggregate(List, AggregationOptions)} instead