Apply fixes from StyleCI

[mechelon]

This pull request applies code style fixes from an analysis carried out by StyleCI.

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[what-the-diff]

PR Summary

• Removed type hinting from method parameters
  This change improves the flexibility of methods by allowing them to accept multiple data types.
• Added missing return types to methods
  With added return types, methods are now more informative and have better code clarity.
• Fixed typos in docblocks and comments
  Miscellaneous typo fixes improve documentation readability and overall understanding.