get_attributes() raises AttributeError on Office example

[jkirsch-patreon]

Using the office model from examples, Office.get_attributes() raises an AttributeError exception.

>>> Office.get_attributes()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/dev/patreon_py/venv/lib/python3.9/site-packages/pynamodb/attributes.py", line 554, in __repr__
    fields = ', '.join(f'{k}={v!r}' for k, v in self.attribute_values.items())
  File "/home/dev/patreon_py/venv/lib/python3.9/site-packages/pynamodb/attributes.py", line 1095, in __getattr__
    raise AttributeError("'{}' has no attribute '{}'".format(self.__class__.__name__, attr))
AttributeError: 'Location' has no attribute 'attribute_values'

[jkirsch-patreon]

But Thread.get_attributes() from examples does not. I believe it is due to attributes of Office which are subclass of MapAttribute