How does one use AssertCalled (when testing with mock objects)?

This form keeps hanging on me, so I'll paste an image from the previous (hung) session:

https://www.mathworks.com/help/matlab/ref/matlab.mock.testcase.assertcalled.html

Basically, I'm guessing the mock object is the "behavior".

That doesn't seem right, but that page gives no other clue...

The generate function is declared as:

function [trajectory] = generate(this) %#codegen

That is, it's a public class function with no other inputs except the mandatory first parameter.

How do I get this to work?

[Tommy]

I may be misunderstanding the docs but it seems like you need to request the matlab.mock.MethodCallBehavior object when you call createMock:

[generator, behavior] = this.createMock(?TrajectoryGenerator, ci, {this.simParams, this.simState});

and then

this.assertCalled(behavior.generate(), 'a string');