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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:
 def start(self):
 """ Starts the IOU process. """


        self._check_requirements()
        if not self.is_running():

            yield from self._library_check()

            try:
                self._rename_nvram_file()
            except OSError as e:
                raise IOUError("Could not rename nvram files: {}".format(e))

            iourc_path = self.iourc_path
            if not iourc_path:
                raise IOUError("Could not find an iourc file (IOU license)")
            if not os.path.isfile(iourc_path):
                raise IOUError("The iourc path '{}' is not a regular file".format(iourc_path))

            yield from self._check_iou_licence()
            yield from self._start_ubridge()

            self._create_netmap_config()
            if self.use_default_iou_values:
                # make sure we have the default nvram amount to correctly push the configs
                yield from self.update_default_iou_values()
            self._push_configs_to_nvram()

            # check if there is enough RAM to run
            self.check_available_ram(self.ram)

            self._nvram_watcher = FileWatcher(self._nvram_file(), self._nvram_changed, delay=2)

            # created a environment variable pointing to the iourc file.
            env = os.environ.copy()

            if "IOURC" not in os.environ:
                env["IOURC"] = iourc_path
            command = yield from self._build_command()
            try:
                log.info("Starting IOU: {}".format(command))
                self.command_line = ' '.join(command)
                self._iou_process = yield from asyncio.create_subprocess_exec(
                    *command,
                    stdout=asyncio.subprocess.PIPE,
                    stdin=asyncio.subprocess.PIPE,
                    stderr=subprocess.STDOUT,
                    cwd=self.working_dir,
                    env=env)
                log.info("IOU instance {} started PID={}".format(self._id, self._iou_process.pid))
                self._started = True
                self.status = "started"
                callback = functools.partial(self._termination_callback, "IOU")
                gns3server.utils.asyncio.monitor_process(self._iou_process, callback)
            except FileNotFoundError as e:
                raise IOUError("Could not start IOU: {}: 32-bit binary support is probably not installed".format(e))
            except (OSError, subprocess.SubprocessError) as e:
                iou_stdout = self.read_iou_stdout()
                log.error("Could not start IOU {}: {}\n{}".format(self._path, e, iou_stdout))
                raise IOUError("Could not start IOU {}: {}\n{}".format(self._path, e, iou_stdout))

            server = AsyncioTelnetServer(reader=self._iou_process.stdout, writer=self._iou_process.stdin, binary=True, echo=True)
            self._telnet_server = yield from asyncio.start_server(server.run, self._manager.port_manager.console_host, self.console)

            # configure networking support
            yield from self._networking()