Need more unit test coverage:

• make one test file per module (e.g., stac-mjx/utils.py -> tests/test_utils.py) (test_utils.py already exists, so please follow that.)
• put python files defining a function that loads or points to the data in tests/fixtures
• Any required data should be put into a fixture in tests/fixtures.
• Look at codecov report to make sure you have 80% coverage

Follow:

• testing deps: https://github.com/talmolab/sleap-io/blob/5a301106effd8cbcc6f23c9385e3c274b6b9262f/pyproject.toml#L41-L45
• general devops reference: https://github.com/talmolab/sleap-io/blob/main/CONTRIBUTING.md