docs: @PublicEvolving
  	public <ACC, R> SingleOutputStreamOperator<R> aggregate(
  			AggregateFunction<T, ACC, R> function,
  			TypeInformation<ACC> accumulatorType,
  			TypeInformation<R> resultType) {
  
  		checkNotNull(function, "function");
  		checkNotNull(accumulatorType, "accumulatorType");
  		checkNotNull(resultType, "resultType");
  
  		if (function instanceof RichFunction) {
  			throw new UnsupportedOperationException("This aggregation function cannot be a RichFunction.");
  		}
  
  		return aggregate(function, new PassThroughWindowFunction<K, W, R>(),
  			accumulatorType, resultType);
  	}