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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 async def del_unknown_id(self, unknown_id, timeout=OTGW_DEFAULT_TIMEOUT):
 """ Start forwarding the specified Data-ID to the boiler again. This command resets the counter used to determine if the specified Data-ID is supported by the boiler. Return the ID that was marked as supported, or None on failure. This method is a coroutine """

        cmd = OTGW_CMD_KNOWN_ID
        unknown_id = int(unknown_id)
        if unknown_id < 1 or unknown_id > 255:
            return None
        ret = await self._wait_for_cmd(cmd, unknown_id, timeout)
        if ret is not None:
            return int(ret)