code: def cmd_start(self, argv, help):
          
          parser = argparse.ArgumentParser(
              prog="%s start" % self.progname,
              description=help,
          )
          instances = self.get_instances(command='start')
          parser.add_argument("instance", nargs=1,
                              metavar="instance",
                              help="Name of the instance from the config.",
                              choices=sorted(instances))
          parser.add_argument("-o", "--override", nargs="*", type=str,
                              dest="overrides", metavar="OVERRIDE",
                              help="Option to override in instance config for startup script (name=value).")
          args = parser.parse_args(argv)
          overrides = self._parse_overrides(args)
          overrides['instances'] = self.instances
          instance = instances[args.instance[0]]
          instance.hooks.before_start(instance)
          result = instance.start(overrides)
          instance.hooks.after_start(instance)
          if result is None:
              return
          instance.status()
docs: Starts the instance