driver-legacy/src/main/com/mongodb/DBCollection.java
@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);
    }
@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);
    }
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