-(AlfrescoRequest *) retrieveAvatarForPerson:(AlfrescoPerson *)person
        completionBlock:(AlfrescoContentFileCompletionBlock)completionBlock - retrieves a
        ContentFile object representing the avatar of the specified
      person.
    Parameters
- (AlfrescoPerson *) person
 - The person whose avatar is to be retrieved.
 - (AlfrescoContentFileCompletionBlock) completionBlock
 - The block that is called with the avatar data on completion of the operation. The completion block has the format typedef void (^AlfrescoContentFileCompletionBlock)(AlfrescoContentFile *contentFile, NSError *error).
 
Returns
(AlfrescoRequest *)
Example