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797: Mainline

Now, suppose that you evaluate the fragments shown in Segment 794 and Segment 795 in a workspace, and then you send a change message to the model. Specifically, you send a changed: message to the model with, say, #test as the argument:

Workspace
M := ModelSubclass new. 
V := ViewSubclass new. 
V model: M. 
M changed: #test. 

Because the model receives a changed: message, the model sends an update: message to all dependent parts, one viewer in the example, with #test as the argument. Because the View class defines update: to do nothing in such circumstances, nothing seems to happen.