--- a/AbstractDirectoryBrowser.st	Wed Jan 25 19:02:59 2017 +0000
+++ b/AbstractDirectoryBrowser.st	Wed Feb 01 11:36:30 2017 +0000
@@ -46,6 +46,12 @@
 "
 ! !
 
+!AbstractDirectoryBrowser class methodsFor:'queries'!
+
+isAbstract
+    ^ self == AbstractDirectoryBrowser
+! !
+
 !AbstractDirectoryBrowser methodsFor:'accessing'!
 
 updateToExternFileHolderLock