Add comment as to why there's a single string being returned from Java code and not an array of strings
Revert "Remove usage of "Readonly" module under a hypothesis that it takes up too much time to initialize variables with it" because Readonly slows down only the extractor performance and is considered a good practice in other parts of the code

This reverts commit 08379079b7947ec1ed41b9a7cc4004d6ec7f97a8.
Remove Readonly module from the extractor code-path for performance reasons