code: def _save_config(self, config: ServerConfig):
      def seq_representer(dumper, sequence):
          flow_style = (
              len(sequence) == 0
              or isinstance(sequence[0], str)
              or isinstance(sequence[0], int)
          )
          return dumper.represent_sequence(
              "tag:yaml.org,2002:seq", sequence, flow_style
          )
  
      yaml.add_representer(list, seq_representer)
  
      with open(settings.SERVER_CONFIG_FILE_PATH, "w+") as f:
          yaml.dump(config.dict(), f, sort_keys=False)
  
imports: from pathlib import Path
  from typing import List, Literal, Optional, Union
  import yaml
  from pydantic import BaseModel, Field, root_validator
  from sqlalchemy.ext.asyncio import AsyncSession
  from typing_extensions import Annotated
  from dstack._internal.core.models.backends import AnyConfigInfoWithCreds
  from dstack._internal.core.models.backends.aws import AnyAWSCreds
  from dstack._internal.core.models.backends.azure import AnyAzureCreds
  from dstack._internal.core.models.backends.base import BackendType
  from dstack._internal.core.models.backends.datacrunch import AnyDataCrunchCreds
  from dstack._internal.core.models.backends.lambdalabs import AnyLambdaCreds
  from dstack._internal.core.models.backends.tensordock import AnyTensorDockCreds
  from dstack._internal.core.models.backends.vastai import AnyVastAICreds
  from dstack._internal.core.models.common import ForbidExtra
  from dstack._internal.server import settings
  from dstack._internal.server.models import ProjectModel
  from dstack._internal.server.services import backends
  from dstack._internal.server.services import projects
  from dstack._internal.server.utils.common import run_async
  from dstack._internal.utils.logging import get_logger
label_desc: Use image node_id 3 for calling the ServerConfigManager obj's underlying member method code with example usage: obj._save_config(config) and returns: dumper