--- a/Stream.st	Thu Jun 30 21:12:35 2016 +0100
+++ b/Stream.st	Fri Jul 01 15:31:10 2016 +0100
@@ -533,6 +533,16 @@
     ^ self
 !
 
+errorNotOpen
+    "{ Pragma: +optSpace }"
+
+    "report an error, that the stream has not been opened"
+
+    ^ StreamNotOpenError raiseRequestWith:self  "/ in:thisContext sender
+
+    "Modified: / 8.5.1999 / 20:12:33 / cg"
+!
+
 pastEnd
     "someone tried to read after the end of the stream.
      If signalAtEnd == true, raise a signal. If it's false, return nil.