What problem does this code solve?
Opt methods for JSONArray and JSONObject should allow a default value to be returned.

Risks
Low

Changes to the API?
Yes, new API methods are added where a default parameter is included. The default param is the same type as the return value.

Will this require a new release?
No

Should the documentation be updated?
No

Does it break the unit tests?
No. New unit tests were added for the new API methods.

Was any code refactored in this commit?
No

Review status
APPROVED

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