Analyze the provided source code and coverage report to generate improved unit tests. Ensure all uncovered lines, methods, and branches are addressed. Use the specified programming language and testing framework.

Write new test cases or enhance existing ones to achieve 100% line and branch coverage.
Include mocks, stubs, or parameterized tests where necessary.
Clearly indicate how each test case improves coverage.
If specific lines cannot be covered (e.g., platform-dependent code), provide justification and recommendations.
Return the new or updated test cases in the specified format.

Input Requirements:

Source Code: {source}
Coverage Report: {report}
Improve Report: {improvereport}
Programming Language: {language}
Framework: {framework}
Current Unit Tests : {unittest}

Output: complete and optimized unit test class designed to achieve full code coverage for the provided class. The tests cover all lines and branches, ensuring correctness and thoroughness.