--- a/UnimplementedFunctionalityError.st	Tue Dec 03 21:37:27 2019 +0100
+++ b/UnimplementedFunctionalityError.st	Tue Dec 03 22:30:25 2019 +0100
@@ -1,3 +1,5 @@
+"{ Encoding: utf8 }"
+
 "
  COPYRIGHT (c) 2001 by eXept Software AG
               All Rights Reserved
@@ -14,7 +16,7 @@
 "{ NameSpace: Smalltalk }"
 
 ExecutionError subclass:#UnimplementedFunctionalityError
-	instanceVariableNames:''
+	instanceVariableNames:'lineNumber'
 	classVariableNames:''
 	poolDictionaries:''
 	category:'Kernel-Exceptions-Errors'
@@ -51,6 +53,16 @@
     "Modified: / 01-12-2017 / 12:49:22 / stefan"
 ! !
 
+!UnimplementedFunctionalityError methodsFor:'accessing'!
+
+lineNumber
+    ^ lineNumber
+!
+
+lineNumber:something
+    lineNumber := something.
+! !
+
 !UnimplementedFunctionalityError methodsFor:'printing'!
 
 description
@@ -58,7 +70,10 @@
 
     desc := super description, ': ', originator printString.
     parameter notNil ifTrue:[
-        desc := desc, '>>', parameter selector printString
+        desc := desc, '>>', parameter selector printString.
+        lineNumber notNil ifTrue:[
+            desc := desc,':', lineNumber printString.
+        ].
     ].
     ^ desc
 ! !