code: def cmd_nsh(self, args):
          '''nsh shell commands'''
          usage = "Usage: nsh <start|stop|set>"
          if len(args) < 1:
              print(usage)
              return
          if args[0] == "start":
              self.mpstate.functions.input_handler = self.send
              self.started = True
              self.mpstate.rl.set_prompt("")
          elif args[0] == "stop":
              self.stop()
          elif args[0] == "set":
              self.serial_settings.command(args[1:])
          else:
              print(usagef cmd_nsh(self, args):
          '''nsh shell commands'''
          usage = "Usage: nsh <start|stop|set>"
          if len(args) < 1:
              print(usage)
              return
          if args[0] == "start":
              self.mpstate.functions.input_handler = self.send
              self.started = True
              self.mpstate.rl.set_prompt("")
          elif args[0] == "stop":
              self.stop()
          elif args[0] == "set":
              self.serial_settings.command(args[1:])
          else:
              print(usage)
docs: nsh shell commands