The code was improved by enhancing the docstrings for all functions and adding detailed explanations of parameters, return values, and procedures. Doctests were included to validate the correctness of each function, following the ruff specifications. The Node class now includes an example of usage, demonstrating how to create nodes and access their attributes. The make_symmetric_tree and make_asymmetric_tree functions were updated with doctests to ensure the trees are constructed correctly. Additional tests were added for is_symmetric_tree and is_mirror, showcasing how these functions behave with both symmetric and asymmetric trees.

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
• If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".