<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def start_dev_session(self):
 """ Start a client that attempts to connect to the dev server running on the host `app.dev` """

        try:
            from .dev import DevServerSession
            session = DevServerSession.initialize(host=self.dev)
            session.start()

            #: Save a reference
            self._dev_session = session
        except:
            self.show_error(traceback.format_exc())