code: def _gateway(self) -> Optional[Gateway]:
      return None
  
imports: import shlex
  import sys
  from abc import ABC, abstractmethod
  from typing import Dict, List, Optional
  import dstack.version
  from dstack._internal.core.models.configurations import ConfigurationType, PortMapping, PythonVersion, RegistryAuth
  from dstack._internal.core.models.profiles import SpotPolicy
  from dstack._internal.core.models.runs import AppSpec, DiskRequirements, Gateway, GpusRequirements, JobSpec, Requirements, RetryPolicy, RunSpec
  from dstack._internal.core.services.ssh.ports import filter_reserved_ports
label_desc: Use image node_id 12 for calling the JobConfigurator obj's underlying member method code with example usage: obj._gateway() and returns: None