How to get the response data out of the NSHTTPURLResponse in the callback of AFJSONRequestOperation?

I have a situation where I need to access the raw response data for an AFJSONRequestOperation, from within the callback block which includes only NSHTTPURLResponse. I am able to get the statusCode from the NSHTTPURLResponse, but don't see any way to get to the raw data. Is there a good way that anyone knows of to access this from the failure callback block of this operation?