printOn method corrected (with value)

src/MyCounter/Counter.class.st

@@ -50,3 +50,11 @@ Counter >> initialize [
    super initialize.
 	count := 0
 ]
+
+{ #category : #accessing }
+Counter >> printOn: aStream [
+
+	super printOn: aStream. "a Counter"
+	aStream nextPutAll: ' withValue: ', count printString.
+	aStream cr
+]