code: def scm(self) -> Union["Git", "NoSCM"]:
      from dvc.scm import SCM, SCMError
  
      if self._scm:
          return self._scm
  
      no_scm = self.config["core"].get("no_scm", False)
      try:
          return SCM(self.root_dir, no_scm=no_scm)
      except SCMError:
          if self._uninitialized:
              # might not be a git/dvc repo at all
              # used in `params/metrics/plots` targets
              return SCM(self.root_dir, no_scm=True)
          raise
  
imports: import os
  from collections import defaultdict
  from contextlib import contextmanager
  from functools import wraps
  from typing import TYPE_CHECKING, Callable, ContextManager, Iterable, Optional, Tuple, Union
  from dvc.exceptions import DvcException, NotDvcRepoError, OutputNotFoundError, RevCollectionError
  from dvc.ignore import DvcIgnoreFilter
  from dvc.log import logger
  from dvc.utils.objects import cached_property
label_desc: Use image node_id 10 for calling the Repo obj's underlying member method code with example usage: obj.scm() and returns: self, SCM, SCM