Using Python and the `{unit_test_package}` package, write a suite of unit tests for the function '{function_name}', following the cases above. Include helpful comments to explain each line. Reply only with code, formatted as follows:

```python
# imports
import {unit_test_package}  # used for our unit tests
{{insert other imports as needed}}

# function to test
{function_code}

# unit tests
{package_comment}
{{insert unit test code here}}
```
