code: public static <IN, OUT> SingleOutputStreamOperator<OUT> unorderedWait(
  			DataStream<IN> in,
  			AsyncFunction<IN, OUT> func,
  			long timeout,
  			TimeUnit timeUnit,
  			int capacity) {
  		return addOperator(in, func, timeUnit.toMillis(timeout), capacity, OutputMode.UNORDERED);
  	}
docs: Add an AsyncWaitOperator. The order of output stream records may be reordered.
  
  @param in Input {@link DataStream}
  @param func {@link AsyncFunction}
  @param timeout for the asynchronous operation to complete
  @param timeUnit of the given timeout
  @param capacity The max number of async i/o operation that can be triggered
  @param <IN> Type of input record
  @param <OUT> Type of output record
  @return A new {@link SingleOutputStreamOperator}.