```Traceback (most recent call last): File "/hom...
# marvin-ai
d
Copy code
Traceback (most recent call last):
  File "/home/dave/CODE/RUSTMONSTER/flow.py", line 24, in <module>
    assert cf.Agent('Marvin').model.model_name == sonnet
AttributeError: 'NoneType' object has no attribute 'model_name'