<p>The code passed to eventually never returned normally. Attempted 644 times over 10.013590047 seconds. Last failure message: ArrayBuffer() had length 0 instead of expected length 4.</p>


<pre><code>
      org.scalatest.exceptions.TestFailedDueToTimeoutException: The code passed to eventually never returned normally. Attempted 644 times over 10.013590047 seconds. Last failure message: ArrayBuffer() had length 0 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$$anonfun$5.apply(CoarseGrainedSchedulerBackendSuite.scala:99)
      at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
      at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
      at org.scalatest.Transformer.apply(Transformer.scala:22)
      at org.scalatest.Transformer.apply(Transformer.scala:20)
      at org.scalatest.FunSuiteLike$$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.Suite$class.callExecuteOnSuite$1(Suite.scala:1210)
      at org.scalatest.Suite$$anonfun$runNestedSuites$1.apply(Suite.scala:1257)
      at org.scalatest.Suite$$anonfun$runNestedSuites$1.apply(Suite.scala:1255)
      at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
      at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:186)
      at org.scalatest.Suite$class.runNestedSuites(Suite.scala:1255)
      at org.scalatest.tools.DiscoverySuite.runNestedSuites(DiscoverySuite.scala:30)
      at org.scalatest.Suite$class.run(Suite.scala:1144)
      at org.scalatest.tools.DiscoverySuite.run(DiscoverySuite.scala:30)
      at org.scalatest.tools.SuiteRunner.run(SuiteRunner.scala:45)
      at org.scalatest.tools.Runner$$anonfun$doRunRunRunDaDoRunRun$1.apply(Runner.scala:1340)
      at org.scalatest.tools.Runner$$anonfun$doRunRunRunDaDoRunRun$1.apply(Runner.scala:1334)
      at scala.collection.immutable.List.foreach(List.scala:392)
      at org.scalatest.tools.Runner$.doRunRunRunDaDoRunRun(Runner.scala:1334)
      at org.scalatest.tools.Runner$$anonfun$runOptionallyWithPassFailReporter$2.apply(Runner.scala:1011)
      at org.scalatest.tools.Runner$$anonfun$runOptionallyWithPassFailReporter$2.apply(Runner.scala:1010)
      at org.scalatest.tools.Runner$.withClassLoaderAndDispatchReporter(Runner.scala:1500)
      at org.scalatest.tools.Runner$.runOptionallyWithPassFailReporter(Runner.scala:1010)
      at org.scalatest.tools.Runner$.main(Runner.scala:827)
      at org.scalatest.tools.Runner.main(Runner.scala)
      Cause: org.scalatest.exceptions.TestFailedException: ArrayBuffer() had length 0 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$$anonfun$5$$anonfun$apply$3.apply(CoarseGrainedSchedulerBackendSuite.scala:101)
      at org.apache.spark.scheduler.CoarseGrainedSchedulerBackendSuite$$anonfun$5$$anonfun$apply$3.apply(CoarseGrainedSchedulerBackendSuite.scala:101)
      at org.scalatest.concurrent.Eventually$class.makeAValiantAttempt$1(Eventually.scala:395)
      at org.scalatest.concurrent.Eventually$class.tryTryAgain$1(Eventually.scala:409)
      at org.scalatest.concurrent.Eventually$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$$anonfun$5.apply(CoarseGrainedSchedulerBackendSuite.scala:99)
      at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
      at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
      at org.scalatest.Transformer.apply(Transformer.scala:22)
      at org.scalatest.Transformer.apply(Transformer.scala:20)
      at org.scalatest.FunSuiteLike$$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.Suite$class.callExecuteOnSuite$1(Suite.scala:1210)
      at org.scalatest.Suite$$anonfun$runNestedSuites$1.apply(Suite.scala:1257)
      at org.scalatest.Suite$$anonfun$runNestedSuites$1.apply(Suite.scala:1255)
      at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
      at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:186)
      at org.scalatest.Suite$class.runNestedSuites(Suite.scala:1255)
      at org.scalatest.tools.DiscoverySuite.runNestedSuites(DiscoverySuite.scala:30)
      at org.scalatest.Suite$class.run(Suite.scala:1144)
      at org.scalatest.tools.DiscoverySuite.run(DiscoverySuite.scala:30)
      at org.scalatest.tools.SuiteRunner.run(SuiteRunner.scala:45)
      at org.scalatest.tools.Runner$$anonfun$doRunRunRunDaDoRunRun$1.apply(Runner.scala:1340)
      at org.scalatest.tools.Runner$$anonfun$doRunRunRunDaDoRunRun$1.apply(Runner.scala:1334)
      at scala.collection.immutable.List.foreach(List.scala:392)
      at org.scalatest.tools.Runner$.doRunRunRunDaDoRunRun(Runner.scala:1334)
      at org.scalatest.tools.Runner$$anonfun$runOptionallyWithPassFailReporter$2.apply(Runner.scala:1011)
      at org.scalatest.tools.Runner$$anonfun$runOptionallyWithPassFailReporter$2.apply(Runner.scala:1010)
      at org.scalatest.tools.Runner$.withClassLoaderAndDispatchReporter(Runner.scala:1500)
      at org.scalatest.tools.Runner$.runOptionallyWithPassFailReporter(Runner.scala:1010)
      at org.scalatest.tools.Runner$.main(Runner.scala:827)
      at org.scalatest.tools.Runner.main(Runner.scala)
</code></pre>