--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/TypeLibrary.java	Fri Oct 11 20:17:18 2019 +0200
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/TypeLibrary.java	Fri Oct 11 20:19:08 2019 +0200
@@ -407,6 +407,7 @@
     // Purpose of this method is to mark types that are reachable
     // from registered event types. Those types that are not reachable can
     // safely be removed
+    // Returns true if type was removed
     public boolean clearUnregistered() {
         Logger.log(LogTag.JFR_METADATA, LogLevel.TRACE, "Cleaning out obsolete metadata");
         List<Type> registered = new ArrayList<>();