--- a/ImageReader.st	Fri Feb 10 11:18:11 2017 +0100
+++ b/ImageReader.st	Fri Feb 10 11:19:43 2017 +0100
@@ -1734,6 +1734,16 @@
     "Modified (comment): / 05-02-2017 / 16:58:11 / cg"
 ! !
 
+!ImageReader class methodsFor:'queries'!
+
+isAbstract
+    "Return if this class is an abstract class.
+     True is returned here for myself only; false for subclasses.
+     Abstract subclasses must redefine this again."
+
+    ^ self == ImageReader.
+! !
+
 !ImageReader class methodsFor:'testing'!
 
 canRepresent:anImage