Caused by: java.lang.NullPointerException
at StreamExecCalc$1148.processElement_split178(Unknown Source) ~[?:?]
at StreamExecCalc$1148.processElement(Unknown Source) ~[?:?]
at org.apache.flink.streaming.runtime.tasks.CopyingChainingOutput.pushToOperator(CopyingChainingOutput.java:82) ~[flink-dist-1.15.1.jar:1.15.1]
at org.apache.flink.streaming.runtime.tasks.CopyingChainingOutput.collect(CopyingChainingOutput.java:57) ~[flink-dist-1.15.1.jar:1.15.1]
at org.apache.flink.streaming.runtime.tasks.CopyingChainingOutput.collect(CopyingChainingOutput.java:29) ~[flink-dist-1.15.1.jar:1.15.1]
at org.apache.flink.streaming.api.operators.CountingOutput.collect(CountingOutput.java:56) ~[flink-dist-1.15.1.jar:1.15.1]
at org.apache.flink.streaming.api.operators.CountingOutput.collect(CountingOutput.java:29) ~[flink-dist-1.15.1.jar:1.15.1]
at org.apache.flink.streaming.api.operators.TimestampedCollector.collect(TimestampedCollector.java:51) ~[flink-dist-1.