'Return a generator which yields object data.
:param obj: Object instance
:type obj: :class:`Object`
:param chunk_size: Optional chunk size (in bytes).
:type chunk_size: ``int``
:return: A stream of binary chunks of data.
:rtype: ``object``'

def download_object_as_stream(self, obj, chunk_size=None):

    path = self.get_object_cdn_url(obj)
    with open(path, 'rb') as obj_file:
        for data in read_in_chunks(obj_file, chunk_size=chunk_size):
            (yield data)
