def get_object_data(self, ref):
        """ As get_object_header, but returns object data as well
        :return: (hexsha, type_string, size_as_int,data_string)
        :note: not threadsafe"""
        hexsha, typename, size, stream = self.stream_object_data(ref)
        data = stream.read(size)
        del(stream)
        return (hexsha, typename, size, data)