java.lang.AbstractMethodError

[info] - when calling map(_ * 2) on List(1, 3, 2, 5) - it should be List(2, 6, 4, 10) *** FAILED ***
[info]   Cons(2,Cons(6,Cons(4,Nil()))) did not equal Cons(2,Cons(6,Cons(4,Cons(10,Nil())))) (ListSuite.scala:205)
[info] Exception encountered when attempting to run a suite with class name: scala.test.ListSuite *** ABORTED ***
[info]   java.lang.AbstractMethodError: eve.ops.QueueStackOps$$anon$1.flatMap(Ljava/lang/Object;Lminiboxing/internal/MiniboxedFunction1;Ljava/lang/Object;Leve/$tilde$greater;)Ljava/lang/Object;
[info]   at eve.ops.Flatmaps$FlatmapOps.flatMap(Flatmaps.scala:37)
[info]   at scala.test.ListSuite$$anonfun$44.apply$J(ListSuite.scala:209)
[info]   at miniboxing.internal.AbstractMiniboxedFunction0$J$$anon$2.apply(MiniboxedFunction.scala:74)
[info]   at org.scalatest.Transformer$$anonfun$apply$1.apply$mcV$sp(Transformer.scala:22)
[info]   at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
[info]   at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
[info]   at org.scalatest.Transformer.apply(Transformer.scala:22)
[info]   at org.scalatest.Transformer.apply(Transformer.scala:20)
[info]   at org.scalatest.FunSuiteLike$$anon$1.apply(FunSuiteLike.scala:166)
[info]   at org.scalatest.Suite$class.withFixture(Suite.scala:1122)
[info]   ...