Target file. If file exists and overwrite is false, do not call url,
just use current file. If file does not exist or overwrite is true, call url, save
result in file, and process file. Must not be null.
Processor for result of call to api.php.
result of processing
if followRedirects is false and this language is redirected
to another language. The message of the HttpRetryException is the target language.
if another error occurs