Parse: How to use PFFile getDataStreamInBackgroundWithBlock efficiently

Question

I am using Parse's getDataStreamInBackgroundWithBlock method to download a large file and save it locally.

How can I to process the stream to store the data in a file? Is this possible without using NSInputStream delegate methods (hasBytesAvailable etc)?

[databaseFile getDataStreamInBackgroundWithBlock:
     ^(NSInputStream *stream, NSError *error) {
            // 
}];