--- a/src/Tools/Graphview/mutator.scala Tue Feb 11 23:31:12 2025 +0100
+++ b/src/Tools/Graphview/mutator.scala Wed Feb 12 00:40:57 2025 +0100
@@ -11,7 +11,6 @@
import isabelle._
import java.awt.Color
-import scala.collection.immutable.SortedSet
object Mutator {