src/Tools/jEdit/src/prover/MarkupNode.scala

 import javax.swing._
 import javax.swing.text.Position
 import javax.swing.tree._
 
 abstract class MarkupInfo
-case class RootInfo extends MarkupInfo
+case class RootInfo() extends MarkupInfo
 case class OuterInfo(highlight: String) extends MarkupInfo {override def toString = highlight}
 case class HighlightInfo(highlight: String) extends MarkupInfo {override def toString = highlight}
 case class TypeInfo(type_kind: String) extends MarkupInfo {override def toString = type_kind}
 case class RefInfo(file: Option[String], line: Option[Int],
                    command_id: Option[String], offset: Option[Int]) extends MarkupInfo {