docs: @Internal
  	public <R> SingleOutputStreamOperator<R> process(
  			CoProcessFunction<IN1, IN2, R> coProcessFunction,
  			TypeInformation<R> outputType) {
  
  		TwoInputStreamOperator<IN1, IN2, R> operator;
  
  		if ((inputStream1 instanceof KeyedStream) && (inputStream2 instanceof KeyedStream)) {
  			operator = new KeyedCoProcessOperator<>(inputStream1.clean(coProcessFunction));
  		} else {
  			operator = new CoProcessOperator<>(inputStream1.clean(coProcessFunction));
  		}
  
  		return transform("Co-Process", outputType, operator);
  	}