def file_download_event_builder(event, sender_app, obj=None, **kwargs):
event.update(dict(<EOL>timestamp=datetime.datetime.utcnow().isoformat(),<EOL>bucket_id=str(obj.bucket_id),<EOL>file_id=str(obj.file_id),<EOL>file_key=obj.key,<EOL>size=obj.file.size,<EOL>referrer=request.referrer,<EOL>**get_user()<EOL>))<EOL>return event<EOL>
Build a file-download event.