Add override for stageId, stageAttemptId and partitionId.

Updating wording in TaskContext.stageAttemptId

Author: advancedxy

core/src/main/scala/org/apache/spark/TaskContext.scala

@@ -151,7 +151,9 @@ abstract class TaskContext extends Serializable {
   def stageId(): Int
 
   /**
-   * An ID that is unique to the stage attempt that this task belongs to.
+   * An ID that is unique to the stage attempt that this task belongs to. It represents how many
+   * times the stage has been attempted. The first stage attempt will be assigned stageAttemptId = 0
+   * , and subsequent attempts will increasing stageAttemptId one by one.
    */
   def stageAttemptId(): Int
 

core/src/main/scala/org/apache/spark/TaskContextImpl.scala

@@ -41,9 +41,9 @@ import org.apache.spark.util._
  * `TaskMetrics` & `MetricsSystem` objects are not thread safe.
  */
 private[spark] class TaskContextImpl(
-    val stageId: Int,
-    val stageAttemptId: Int,
-    val partitionId: Int,
+    override val stageId: Int,
+    override val stageAttemptId: Int,
+    override val partitionId: Int,
     override val taskAttemptId: Long,
     override val attemptNumber: Int,
     override val taskMemoryManager: TaskMemoryManager,