<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _write(self):
 """ Writes data from backup_dict property in serialized and compressed form to backup file pointed in json_file property. """

        self.json_file.seek(0)
        self.json_file.truncate()
        dump = json.dumps(self.backup_dict)
        dump_c = zlib.compress(dump.encode('utf-8'))
        self.json_file.write(dump_c)