Fix JSON output order by using LinkedHashMap/LinkedHashSet

[seijikohara]

Proposed Changes

This pull request aims to fix the issue of inconsistent JSON output order by replacing HashMap and HashSet with LinkedHashMap and LinkedHashSet, respectively.

Motivation

Currently, when using HashMap or HashSet, the order of elements in the JSON output is random and changes with each execution. This can lead to readability issues, especially when dealing with large and complex JSON structures.

Implementation

• Replace all instances of HashMap with LinkedHashMap to preserve the insertion order of key-value pairs in the JSON output.
• Replace all instances of HashSet with LinkedHashSet to preserve the insertion order of elements in the JSON output.

By using LinkedHashMap and LinkedHashSet, the JSON output order will now follow the order in which elements were inserted, improving readability and consistency.

Please review the changes and let me know if any further modifications are needed.