org.scalatest.exceptions.TestFailedDueToTimeoutException: The code passed to eventually never returned normally. Attempted 315 times over 10.586973218 seconds. Last failure message: ArrayBuffer("2", "1", "0") had length 3 instead of expected length 4.

sbt.ForkMain$ForkError: org.scalatest.exceptions.TestFailedDueToTimeoutException: The code passed to eventually never returned normally. Attempted 315 times over 10.586973218 seconds. Last failure message: ArrayBuffer("2", "1", "0") had length 3 instead of expected length 4.
	at org.scalatest.concurrent.Eventually$class.tryTryAgain$1(Eventually.scala:421)
	at org.scalatest.concurrent.Eventually$class.eventually(Eventually.scala:439)
	at org.apache.spark.scheduler.CoarseGrainedSchedulerBackendSuite.eventually(CoarseGrainedSchedulerBackendSuite.scala:30)
	at org.scalatest.concurrent.Eventually$class.eventually(Eventually.scala:337)
	at org.apache.spark.scheduler.CoarseGrainedSchedulerBackendSuite.eventually(CoarseGrainedSchedulerBackendSuite.scala:30)
	at org.apache.spark.scheduler.CoarseGrainedSchedulerBackendSuite$$anonfun$4.apply(CoarseGrainedSchedulerBackendSuite.scala:67)
	at org.apache.spark.scheduler.CoarseGrainedSchedulerBackendSuite$$anonfun$4.apply(CoarseGrainedSchedulerBackendSuite.scala:61)
	at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
	at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
	at org.scalatest.Transformer.apply(Transformer.scala:22)
	at org.scalatest.Transformer.apply(Transformer.scala:20)
	at org.scalatest.FunSuiteLike$$anon$1.apply(FunSuiteLike.scala:186)
	at org.apache.spark.SparkFunSuite.withFixture(SparkFunSuite.scala:103)
	at org.scalatest.FunSuiteLike$class.invokeWithFixture$1(FunSuiteLike.scala:183)
	at org.scalatest.FunSuiteLike$$anonfun$runTest$1.apply(FunSuiteLike.scala:196)
	at org.scalatest.FunSuiteLike$$anonfun$runTest$1.apply(FunSuiteLike.scala:196)
	at org.scalatest.SuperEngine.runTestImpl(Engine.scala:289)
	at org.scalatest.FunSuiteLike$class.runTest(FunSuiteLike.scala:196)
	at org.apache.spark.scheduler.CoarseGrainedSchedulerBackendSuite.org$scalatest$BeforeAndAfterEach$$super$runTest(CoarseGrainedSchedulerBackendSuite.scala:30)
	at org.scalatest.BeforeAndAfterEach$class.runTest(BeforeAndAfterEach.scala:221)
	at org.apache.spark.scheduler.CoarseGrainedSchedulerBackendSuite.runTest(CoarseGrainedSchedulerBackendSuite.scala:30)
	at org.scalatest.FunSuiteLike$$anonfun$runTests$1.apply(FunSuiteLike.scala:229)
	at org.scalatest.FunSuiteLike$$anonfun$runTests$1.apply(FunSuiteLike.scala:229)
	at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:396)
	at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:384)
	at scala.collection.immutable.List.foreach(List.scala:392)
	at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:384)
	at org.scalatest.SuperEngine.org$scalatest$SuperEngine$$runTestsInBranch(Engine.scala:379)
	at org.scalatest.SuperEngine.runTestsImpl(Engine.scala:461)
	at org.scalatest.FunSuiteLike$class.runTests(FunSuiteLike.scala:229)
	at org.scalatest.FunSuite.runTests(FunSuite.scala:1560)
	at org.scalatest.Suite$class.run(Suite.scala:1147)
	at org.scalatest.FunSuite.org$scalatest$FunSuiteLike$$super$run(FunSuite.scala:1560)
	at org.scalatest.FunSuiteLike$$anonfun$run$1.apply(FunSuiteLike.scala:233)
	at org.scalatest.FunSuiteLike$$anonfun$run$1.apply(FunSuiteLike.scala:233)
	at org.scalatest.SuperEngine.runImpl(Engine.scala:521)
	at org.scalatest.FunSuiteLike$class.run(FunSuiteLike.scala:233)
	at org.apache.spark.SparkFunSuite.org$scalatest$BeforeAndAfterAll$$super$run(SparkFunSuite.scala:52)
	at org.scalatest.BeforeAndAfterAll$class.liftedTree1$1(BeforeAndAfterAll.scala:213)
	at org.scalatest.BeforeAndAfterAll$class.run(BeforeAndAfterAll.scala:210)
	at org.apache.spark.SparkFunSuite.run(SparkFunSuite.scala:52)
	at org.scalatest.tools.Framework.org$scalatest$tools$Framework$$runSuite(Framework.scala:314)
	at org.scalatest.tools.Framework$ScalaTestTask.execute(Framework.scala:480)
	at sbt.ForkMain$Run$2.call(ForkMain.java:296)
	at sbt.ForkMain$Run$2.call(ForkMain.java:286)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: sbt.ForkMain$ForkError: org.scalatest.exceptions.TestFailedException: ArrayBuffer("2", "1", "0") had length 3 instead of expected length 4
	at org.scalatest.Assertions$class.newAssertionFailedException(Assertions.scala:528)
	at org.scalatest.FunSuite.newAssertionFailedException(FunSuite.scala:1560)
	at org.scalatest.Assertions$AssertionsHelper.macroAssert(Assertions.scala:501)
	at org.apache.spark.scheduler.CoarseGrainedSchedulerBackendSuite$$anonfun$4$$anonfun$apply$2.apply(CoarseGrainedSchedulerBackendSuite.scala:69)
	at org.apache.spark.scheduler.CoarseGrainedSchedulerBackendSuite$$anonfun$4$$anonfun$apply$2.apply(CoarseGrainedSchedulerBackendSuite.scala:69)
	at org.scalatest.concurrent.Eventually$class.makeAValiantAttempt$1(Eventually.scala:395)
	at org.scalatest.concurrent.Eventually$class.tryTryAgain$1(Eventually.scala:409)
	... 48 more