Index: trunk/SDToolBox/output_messages.py
===================================================================
diff -u -r60 -r62
--- trunk/SDToolBox/output_messages.py	(.../output_messages.py)	(revision 60)
+++ trunk/SDToolBox/output_messages.py	(.../output_messages.py)	(revision 62)
@@ -23,3 +23,4 @@
 error_needs_to_be_in_subclass = 'Needs to be implemented in subclasses.'
 error_no_gradient_was_calculated = 'No gradient was calculated, ' + \
                                     ' please calculate the gradient on the xarray before proceeding'
+error_function_not_implemented = 'Functionality not implemented.'