Scalastyle standard configuration true true ARROW, EQUALS, ELSE, TRY, CATCH, FINALLY, LARROW, RARROW ARROW, EQUALS, COMMA, COLON, IF, ELSE, DO, WHILE, FOR, MATCH, TRY, CATCH, FINALLY, LARROW, RARROW @VisibleForTesting Runtime\.getRuntime\.addShutdownHook mutable\.SynchronizedBuffer Class\.forName JavaConversions Instead of importing implicits in scala.collection.JavaConversions._, import scala.collection.JavaConverters._ and use .asScala / .asJava methods java,scala,3rdParty,spark javax?\..* scala\..* (?!ml\.dmlc\.xgboost4j\.).* ml.dmlc.xgboost4j.* COMMA 800> 30 10 50 -1,0,1,2,3