code: def start_new_hypervisor(self, working_dir=None):
          
  
          if not self._dynamips_path:
              self.find_dynamips()
  
          if not working_dir:
              working_dir = tempfile.gettempdir()
  
          # FIXME: hypervisor should always listen to 127.0.0.1
          # See https://github.com/GNS3/dynamips/issues/62
          server_config = self.config.get_section_config("Server")
          server_host = server_config.get("host")
  
          try:
              info = socket.getaddrinfo(server_host, 0, socket.AF_UNSPEC, socket.SOCK_STREAM, 0, socket.AI_PASSIVE)
              if not info:
                  raise DynamipsError("getaddrinfo returns an empty list on {}".format(server_host))
              for res in info:
                  af, socktype, proto, _, sa = res
                  # let the OS find an unused port for the Dynamips hypervisor
                  with socket.socket(af, socktype, proto) as sock:
                      sock.bind(sa)
                      port = sock.getsockname()[1]
                      break
          except OSError as e:
              raise DynamipsError("Could not find free port for the Dynamips hypervisor: {}".format(e))
  
          port_manager = PortManager.instance()
          hypervisor = Hypervisor(self._dynamips_path, working_dir, server_host, port, port_manager.console_host)
  
          log.info("Creating new hypervisor {}:{} with working directory {}".format(hypervisor.host, hypervisor.port, working_dir))
          yield from hypervisor.start()
          log.info("Hypervisor {}:{} has successfully started".format(hypervisor.host, hypervisor.port))
          yield from hypervisor.connect()
          if parse_version(hypervisor.version) < parse_version('0.2.11'):
              raise DynamipsError("Dynamips version must be >= 0.2.11, detected version is {}".format(hypervisor.version))
  
          return hypervisor
docs: Creates a new Dynamips process and start it.
  
          :param working_dir: working directory
  
          :returns: the new hypervisor instance