--- a/ExternalAddress.st	Thu Apr 11 08:55:36 2019 +0200
+++ b/ExternalAddress.st	Thu Apr 11 10:50:39 2019 +0200
@@ -430,6 +430,18 @@
     "Modified: / 07-08-2006 / 15:16:32 / fm"
 ! !
 
+!ExternalAddress methodsFor:'queries'!
+
+isValid
+    "true if I have an address"
+
+%{  /* NOCONTEXT */
+    RETURN ((__INST(address_) == 0) ? false : true );
+%}
+
+    "Created: / 11-04-2019 / 10:50:31 / Claus Gittinger"
+! !
+
 !ExternalAddress methodsFor:'testing'!
 
 isExternalAddress