多个inputstream的情况下，watermark的值怎么赋值？

1,
org.apache.flink.streaming.api.operators; AbstractStreamOperator

public void processWatermark1(Watermark mark) throws Exception {
   input1Watermark = mark.getTimestamp();
   long newMin = Math.min(input1Watermark, input2Watermark);
   if (newMin > combinedWatermark) {
      combinedWatermark = newMin;
      processWatermark(new Watermark(combinedWatermark));
   }
}

public void processWatermark2(Watermark mark) throws Exception {
   input2Watermark = mark.getTimestamp();
   long newMin = Math.min(input1Watermark, input2Watermark);
   if (newMin > combinedWatermark) {
      combinedWatermark = newMin;
      processWatermark(new Watermark(combinedWatermark));
   }
}

2,
http://vinoyang.com/2016/10/29/flink-streaming-window-operator-analysis/