--- a/UndefinedObject.st	Thu Feb 09 15:14:34 2023 +0000
+++ b/UndefinedObject.st	Thu Feb 09 15:22:39 2023 +0000
@@ -1,6 +1,7 @@
 "
  COPYRIGHT (c) 1988 by Claus Gittinger
  COPYRIGHT (c) 2015 Jan Vrany
+ COPYRIGHT (c) 2023 LabWare
 	      All Rights Reserved
 
  This software is furnished under a license and may be used
@@ -27,6 +28,7 @@
 "
  COPYRIGHT (c) 1988 by Claus Gittinger
  COPYRIGHT (c) 2015 Jan Vrany
+ COPYRIGHT (c) 2023 LabWare
 	      All Rights Reserved
 
  This software is furnished under a license and may be used
@@ -156,6 +158,7 @@
 ! !
 
 
+
 !UndefinedObject methodsFor:'Compatibility-Squeak'!
 
 subclass:nameSymbol instanceVariableNames:instVarNameString classVariableNames:classVarString category:cat
@@ -178,6 +181,19 @@
     ^ self
 !
 
+doIfNotNil:aBlock
+    "if I am a collection, then enumerate myself into aBlock.
+     if I am nil, then do nothing.
+     Return the receiver.
+     Otherwise, evaluate aBlock with myself as argument. 
+     Here, answer nil"
+
+    ^ nil
+
+    "Created: / 20-03-2018 / 15:37:11 / stefan"
+    "Modified (comment): / 05-08-2018 / 11:26:32 / Claus Gittinger"
+!
+
 literalArrayEncoding
     "encode myself as an array literal, from which a copy of the receiver
      can be reconstructed with #decodeAsLiteralArray."
@@ -309,7 +325,6 @@
     ^ 0
 ! !
 
-
 !UndefinedObject methodsFor:'subclass creation'!
 
 nilSubclass:action
@@ -751,6 +766,11 @@
 
 version_CVS
     ^ '$Header$'
+!
+
+version_HG
+
+    ^ '$Changeset: <not expanded> $'
 ! !