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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, script, interpreter=sys.executable, args=None, error_callback=None, reuse=False):
 """ Starts the backend process. The backend is a python script that starts a :class:`pyqode.core.backend.JsonServer`. You must write the backend script so that you can apply your own backend configuration. The script can be run with a custom interpreter. The default is to use sys.executable. .. note:: This restart the backend process if it was previously running. :param script: Path to the backend script. :param interpreter: The python interpreter to use to run the backend script. If None, sys.executable is used unless we are in a frozen application (frozen backends do not require an interpreter). :param args: list of additional command line args to use to start the backend process. :param reuse: True to reuse an existing backend process. WARNING: to use this, your application must have one single server script. If you're creating an app which supports multiple programming languages you will need to merge all backend scripts into one single script, otherwise the wrong script might be picked up). """

        self._shared = reuse
        if reuse and BackendManager.SHARE_COUNT:
            self._port = BackendManager.LAST_PORT
            self._process = BackendManager.LAST_PROCESS
            BackendManager.SHARE_COUNT += 1
        else:
            if self.running:
                self.stop()
            self.server_script = script
            self.interpreter = interpreter
            self.args = args
            backend_script = script.replace('.pyc', '.py')
            self._port = self.pick_free_port()
            if hasattr(sys, "frozen") and not backend_script.endswith('.py'):
                # frozen backend script on windows/mac does not need an
                # interpreter
                program = backend_script
                pgm_args = [str(self._port)]
            else:
                program = interpreter
                pgm_args = [backend_script, str(self._port)]
            if args:
                pgm_args += args
            self._process = BackendProcess(self.editor)
            if error_callback:
                self._process.error.connect(error_callback)
            self._process.start(program, pgm_args)

            if reuse:
                BackendManager.LAST_PROCESS = self._process
                BackendManager.LAST_PORT = self._port
                BackendManager.SHARE_COUNT += 1
            comm('starting backend process: %s %s', program,
                 ' '.join(pgm_args))
            self._heartbeat_timer.start()