prod_pr - manual review

• /FreqTableExampleOriginal.java
• /IntListVer2.java

Summary by Bito

This pull request introduces several new Java classes that extend functionality across different areas of the application, including an airline mileage redemption system, binary conversion utility, frequency table generator, and dynamically resizing integer list. Additionally, it addresses corrections in the AirlineProblem.java file by refining conditional checks, adjusting variable types, and amending string concatenation to resolve bugs affecting airline processing routines. Each component is built with careful exception handling, validations, and assertions to ensure robustness. Overall, these additions and corrections provide a solid base for new features while enhancing code reliability and consistency.