Generate Unit Tests

Create comprehensive unit tests for the following [PROGRAMMING LANGUAGE] code using [TEST FRAMEWORK].

**Test Requirements:**
1. **Happy Path:** Test normal, expected flow with valid inputs
2. **Edge Cases:** Test boundary values, empty inputs, null values, and extreme cases
3. **Error Handling:** Test invalid inputs and expected exceptions
4. **Boundary Testing:** Test limits of ranges and data types

**Test Structure:**
- Use the AAA pattern (Arrange-Act-Assert)
- Give each test a descriptive name
- Group related tests logically
- Use mocks/stubs for external dependencies where needed

**Additionally:**
- Estimate the code coverage of the tests
- Suggest additional test scenarios that are not obvious
- Consider [SPECIAL REQUIREMENTS]

Code to test:
```[PROGRAMMING LANGUAGE]
[INSERT CODE HERE]
```

Replace placeholders in [square brackets]: [PROGRAMMING LANGUAGE][TEST FRAMEWORK][SPECIAL REQUIREMENTS][INSERT CODE HERE]