docs: public <L, R> SingleOutputStreamOperator<R> flatSelect(
  			final OutputTag<L> timedOutPartialMatchesTag,
  			final PatternFlatTimeoutFunction<T, L> patternFlatTimeoutFunction,
  			final PatternFlatSelectFunction<T, R> patternFlatSelectFunction) {
  
  		final TypeInformation<R> rightTypeInfo = TypeExtractor.getUnaryOperatorReturnType(
  			patternFlatSelectFunction,
  			PatternFlatSelectFunction.class,
  			0,
  			1,
  			new int[]{1, 0},
  			builder.getInputType(),
  			null,
  			false);
  
  		return flatSelect(
  			timedOutPartialMatchesTag,
  			patternFlatTimeoutFunction,
  			rightTypeInfo,
  			patternFlatSelectFunction);
  	}