A class to define an optional property in a JSON object, for use in conjunction with kjson
 | Unifying Business, Data, and Code: Designing Data Products with JSON Schema (2024) by Itelman, Ron, Viotti, Juan Cruz |
 | JSON at Work: Practical Data Integration for the Web (2017) by Marrs, Tom |
 | Introduction to JavaScript Object Notation: A To-the-Point Guide to JSON (2015) by Bassett, Lindsay |
 | Json for Beginners: Your Guide to Easily Learn Json In 7 Days (Programming Languages) (2017) by Academy, iCode |