org.apache.spark.SparkException: A master URL must be set in your configuration

sbt.ForkMain$ForkError: org.apache.spark.SparkException: A master URL must be set in your configuration
	at org.apache.spark.SparkContext.<init>(SparkContext.scala:369)
	at org.apache.spark.SparkContext$.getOrCreate(SparkContext.scala:2541)
	at org.apache.spark.sql.SparkSession$Builder$$anonfun$7.apply(SparkSession.scala:944)
	at org.apache.spark.sql.SparkSession$Builder$$anonfun$7.apply(SparkSession.scala:935)
	at scala.Option.getOrElse(Option.scala:121)
	at org.apache.spark.sql.SparkSession$Builder.getOrCreate(SparkSession.scala:935)
	at org.apache.spark.ml.util.BaseReadWrite$class.sparkSession(ReadWrite.scala:76)
	at org.apache.spark.ml.util.MLWriter.sparkSession(ReadWrite.scala:169)
	at org.apache.spark.ml.util.BaseReadWrite$class.sc(ReadWrite.scala:87)
	at org.apache.spark.ml.util.MLWriter.sc(ReadWrite.scala:169)
	at org.apache.spark.ml.util.MLWriter.save(ReadWrite.scala:179)
	at org.apache.spark.ml.util.MLWritable$class.save(ReadWrite.scala:306)
	at org.apache.spark.ml.tuning.CrossValidatorModel.save(CrossValidator.scala:254)
	at org.apache.spark.ml.util.DefaultReadWriteTest$class.testDefaultReadWrite(DefaultReadWriteTest.scala:52)
	at org.apache.spark.ml.tuning.CrossValidatorSuite.testDefaultReadWrite(CrossValidatorSuite.scala:37)
	at org.apache.spark.ml.tuning.CrossValidatorSuite$$anonfun$13.apply(CrossValidatorSuite.scala:420)
	at org.apache.spark.ml.tuning.CrossValidatorSuite$$anonfun$13.apply(CrossValidatorSuite.scala:404)
	at org.scalatest.OutcomeOf$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$$anonfun$runTest$1.apply(FunSuiteLike.scala:196)
	at org.scalatest.SuperEngine.runTestImpl(Engine.scala:289)
	at org.scalatest.FunSuiteLike$class.runTest(FunSuiteLike.scala:196)
	at org.apache.spark.ml.tuning.CrossValidatorSuite.org$scalatest$BeforeAndAfterEach$$super$runTest(CrossValidatorSuite.scala:37)
	at org.scalatest.BeforeAndAfterEach$class.runTest(BeforeAndAfterEach.scala:221)
	at org.apache.spark.ml.tuning.CrossValidatorSuite.runTest(CrossValidatorSuite.scala:37)
	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$2.call(ForkMain.java:286)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)