Major Description
just run the following code
val a = spark.createDataFrame(sc.parallelize(Seq((1,2),(3,4)))).as[(Int,Int)]
val grouped = a.groupByKey({x:(Int,Int)=>x._1})
val mappedGroups = grouped.mapGroups((k,x)=>{(k,1)})
val yyy = sc.broadcast(1)
val last = mappedGroups.rdd.map(xx=>{
val simpley = yyy.value
1
})
spark says Task not serializable
