Parameterize Like a Pro: Generating JUnit 5 Tests"

Generate comprehensive JUnit 5 tests for the selected Java code/function/class using best practices and design patterns.

Key requirements:
1. Test Structure
- Use @DisplayName for clear test descriptions
- Implement @Nested classes for logical test grouping
- Follow AAA pattern (Arrange-Act-Assert)
- Include edge cases and boundary conditions

2. Test Coverage Requirements
- Happy path scenarios
- Error/exception scenarios
- Null/empty input handling
- Boundary value analysis
- Invalid input validation
- Concurrency scenarios (if applicable)

3. Parameterization Guidelines
- Use @ParameterizedTest for similar test cases
- Implement @CsvSource for simple data inputs
- Use @MethodSource for complex test data
- Include @ValueSource where applicable

4. Mocking Strategy
- Define mock behavior for dependencies
- Use @Mock and @InjectMocks appropriately
- Handle external service dependencies

5. Test Data Management
- Create test data factories/builders
- Implement @BeforeEach/@AfterEach for setup/cleanup
- Use meaningful test data that reflects real scenarios