Remove Duplication

When removing duplicated code:

1. Identify the duplicated code blocks. Are they truly identical, or just similar?
2. If identical: extract the common code into a shared function or module.
3. If similar: identify the differences. Parameterize the shared function to handle the variations.
4. Replace each duplicate with a call to the shared function.
5. Run the tests after each replacement to verify behavior is preserved.
6. Don’t force it. If the code is similar but serves different purposes, duplication is acceptable — premature abstraction is worse than repetition.