code: public SingleOutputStreamOperator<T> max(int positionToMax) {
  		return aggregate(new ComparableAggregator<>(positionToMax, input.getType(), AggregationFunction.AggregationType.MAX, input.getExecutionConfig()));
  	}
docs: Applies an aggregation that gives the maximum value of every window of
  the data stream at the given position.
  
  @param positionToMax The position to maximize
  @return The transformed DataStream.