Exception in thread "main" scala.MatchError: Test$B.this.f()
        at scala.tools.nsc.transform.Mixin$MixinTransformer$$anonfun$22.apply(Mixin.scala:581)
        at scala.tools.nsc.transform.Mixin$MixinTransformer$$anonfun$22.apply(Mixin.scala:578)
        at scala.List.map(List.scala:683)
        at scala.tools.nsc.transform.Mixin$MixinTransformer.lazifyOwnFields$0(Mixin.scala:578)
        at scala.tools.nsc.transform.Mixin$MixinTransformer.addNewDefs(Mixin.scala:595)
        at scala.tools.nsc.transform.Mixin$MixinTransformer.scala$tools$nsc$transform$Mixin$MixinTransformer$$po\
stTransform(Mixin.scala:682)
        at scala.tools.nsc.transform.Mixin$MixinTransformer$$anonfun$34.apply(Mixin.scala:785)
        at scala.tools.nsc.transform.Mixin$MixinTransformer$$anonfun$34.apply(Mixin.scala:785)
        at scala.tools.nsc.symtab.SymbolTable.atPhase(SymbolTable.scala:85)
        at scala.tools.nsc.transform.Mixin$MixinTransformer.transform(Mixin.scala:785)
        at scala.tools.nsc.ast.Trees$Transformer.transformTemplate(Trees.scala:1311)
        at scala.tools.nsc.ast.Trees$Transformer$$anonfun$21.apply(Trees.scala:1209)
        at scala.tools.nsc.ast.Trees$Transformer$$anonfun$21.apply(Trees.scala:1209)
        at scala.tools.nsc.ast.Trees$Transformer.atOwner(Trees.scala:1333)
        at scala.tools.nsc.ast.Trees$Transformer.transform(Trees.scala:1208)
        at scala.tools.nsc.transform.Mixin$MixinTransformer.transform(Mixin.scala:784)
        at scala.tools.nsc.ast.Trees$Transformer$$anonfun$33.apply(Trees.scala:1327)
        at scala.tools.nsc.ast.Trees$Transformer$$anonfun$33.apply(Trees.scala:1325)
        ...