had a not serializable result: com.tencent.angel.ml.math2.utils.LabeledData

Serialization stack:
- object not serializable (class: com.tencent.angel.ml.math2.utils.LabeledData, value: com.tencent.angel.ml.math2.utils.LabeledData@4da494b8)
2020-05-09 18:05:47 INFO DAGScheduler:54 - Job 0 failed: count at FTRLExample.scala:109, took 0.395223 s
Exception in thread "main" org.apache.spark.SparkException: Job aborted due to stage failure: Task 0.0 in stage 0.0 (TID 0) had a not serializable result: com.tencent.angel.ml.math2.utils.LabeledData
Serialization stack:
- object not serializable (class: com.tencent.angel.ml.math2.utils.LabeledData, value: com.tencent.angel.ml.math2.utils.LabeledData@4da494b8)
at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1599)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1587)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1586)
at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)
at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1586)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:831)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:831)
at scala.Option.foreach(Option.scala:257)
at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:831)
at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:1820)
at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1769)
at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1758)
at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48)
at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:642)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:2027)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:2048)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:2067)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:2092)
at org.apache.spark.rdd.RDD.count(RDD.scala:1162)
at com.tencent.angel.sona.examples.online_learning.FTRLExample$.train(FTRLExample.scala:109)
at com.tencent.angel.sona.examples.online_learning.FTRLExample$.main(FTRLExample.scala:51)
at com.tencent.angel.sona.examples.online_learning.FTRLExample.main(FTRLExample.scala)