scala.tools.nsc.FatalError: Companions 'object RationalTest' and 'class RationalTest' must be defined in same file.
        at scala.tools.nsc.symtab.Symbols$Symbol.isCoDefinedWith(Symbols.java:1221)
        at scala.tools.nsc.symtab.Symbols$Symbol$$anonfun$linkedSym$1.apply(Symbols.java:1250)
        at scala.tools.nsc.symtab.Symbols$Symbol$$anonfun$linkedSym$1.apply(Symbols.java:1250)
        at scala.tools.nsc.symtab.Symbols$Symbol.filter(Symbols.java:1033)
        at scala.tools.nsc.symtab.Symbols$Symbol.suchThat(Symbols.java:1037)
        at scala.tools.nsc.symtab.Symbols$Symbol.linkedSym(Symbols.java:1250)
        at scala.tools.nsc.typechecker.Namers$Namer.updatePosFlags(Namers.java:94)
        at scala.tools.nsc.typechecker.Namers$Namer.enterClassSymbol(Namers.java:201)
        at scala.tools.nsc.typechecker.Namers$Namer.enterSym(Namers.java:340)
        at scala.tools.nsc.typechecker.Namers$Namer$$anonfun$enterSyms$1.apply(Namers.java:255)
        at scala.tools.nsc.typechecker.Namers$Namer$$anonfun$enterSyms$1.apply(Namers.java:254)
        at scala.collection.LinearSeqLike$class.foreach(LinearSeqLike.java:85)
        at scala.collection.immutable.List.foreach(List.java:29)
        at scala.tools.nsc.typechecker.Namers$Namer.enterSyms(Namers.java:254)
        at scala.tools.nsc.typechecker.Namers$Namer.enterSym(Namers.java:338)
        at scala.tools.nsc.typechecker.Analyzer$namerFactory$$anon$1.apply(Analyzer.java:35)
        at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.java:323)
        at scala.tools.nsc.Global$Run$$anonfun$compileLate$1.apply(Global.java:908)
        at scala.tools.nsc.Global$Run$$anonfun$compileLate$1.apply(Global.java:908)
        at scala.tools.nsc.symtab.SymbolTable.atPhase(SymbolTable.java:98)
        at scala.tools.nsc.Global$Run.compileLate(Global.java:908)
        at org.netbeans.modules.scala.core.interactive.Global.parse(Global.java:258)
        at org.netbeans.modules.scala.core.interactive.Global$$anonfun$reloadSources$1.apply(Global.java:307)
        at org.netbeans.modules.scala.core.interactive.Global$$anonfun$reloadSources$1.apply(Global.java:304)
        at scala.collection.LinearSeqLike$class.foreach(LinearSeqLike.java:85)
        at scala.collection.immutable.List.foreach(List.java:29)
        at org.netbeans.modules.scala.core.interactive.Global.reloadSources(Global.java:304)
        at org.netbeans.modules.scala.core.interactive.Global.typedTreeAt(Global.java:323)
        at org.netbeans.modules.scala.core.interactive.Global.typeMembers(Global.java:419)
        at org.netbeans.modules.scala.core.interactive.Global$$anonfun$getTypeCompletion$1.apply(Global.java:414)
        at org.netbeans.modules.scala.core.interactive.Global$$anonfun$getTypeCompletion$1.apply(Global.java:414)
        at org.netbeans.modules.scala.core.interactive.Global.respond(Global.java:290)
        at org.netbeans.modules.scala.core.interactive.Global.getTypeCompletion(Global.java:414)
        at org.netbeans.modules.scala.core.interactive.CompilerControl$$anon$2.apply(CompilerControl.java:105)
        at org.netbeans.modules.scala.core.interactive.CompilerControl$$anon$2.apply(CompilerControl.java:104)
        at org.netbeans.modules.scala.core.interactive.Global.pollForWork(Global.java:139)
        at org.netbeans.modules.scala.core.interactive.Global$$anon$2.run(Global.java:200)