HelperFunctions useMappedObjects(List<Object> list) throws IndexOutOfBoundsExceptions when it tries to add values to the list which will be returned. This happens because the list with replaced values gets initialized as empty and the value is being added using lists set method, which requires an existing item in the given index. Since the list is empty an IndexOutOfBoundsException gets thrown.

This can also cause some odd behaviour with exception handling when it is combined with waitUntil keywords, resulting in massive amounts of seemingly random exception output in logs.