class_docstr: Representation of a Git repository
  
      
docstr: Add fake dates to `env`.
  
  Parameters
  ----------
  env : dict, optional
      Environment variables.
  
  Returns
  -------
  A dict (copied from env), with date-related environment
  variables for git and git-annex set.
docstr_tok: ["Add","fake","dates","to","`","env","`",".","Parameters","--","--","--","--","--","env",":","dict",",","optional","Environment","variables",".","Returns","--","--","--","-","A","dict","(","copied","from","env",")",",","with","date-related","environment","variables","for","git","and","git-annex","set","."]
code: def add_fake_dates_to_env(self, env=None):
      """Add fake dates to `env`.
  
      Parameters
      ----------
      env : dict, optional
          Environment variables.
  
      Returns
      -------
      A dict (copied from env), with date-related environment
      variables for git and git-annex set.
      """
      env = (env if env is not None else environ).copy()
      # Note: Use _git_custom_command here rather than repo.git.for_each_ref
      # so that we use annex-proxy in direct mode.
      last_date = list(
          self.for_each_ref_(
              fields="committerdate:raw",
              count=1,
              pattern="refs/heads",
              sort="-committerdate",
          )
      )
  
      if last_date:
          # Drop the "contextual" timezone, leaving the unix timestamp.  We
          # avoid :unix above because it wasn't introduced until Git v2.9.4.
          last_date = last_date[0]["committerdate:raw"].split()[0]
          seconds = int(last_date)
      else:
          seconds = self.cfg.obtain("datalad.fake-dates-start")
      seconds_new = seconds + 1
      date = "@{} +0000".format(seconds_new)
  
      lgr.debug(
          "Setting date to %s",
          time.strftime(
              "%a %d %b %Y %H:%M:%S +0000", time.gmtime(seconds_new)
          ),
      )
  
      env["GIT_AUTHOR_DATE"] = date
      env["GIT_COMMITTER_DATE"] = date
      env["GIT_ANNEX_VECTOR_CLOCK"] = str(seconds_new)
  
      return env
  
imports: import logging
  import re
  import threading
  import time
  from contextlib import contextmanager
  from locale import getpreferredencoding
  from os import environ
  from os.path import lexists
  from typing import Optional
  from weakref import finalize, WeakValueDictionary
  from datalad.cmd import GitWitlessRunner, StdOutErrCapture
  from datalad.config import ConfigManager
  from datalad.dataset.repo import PathBasedFlyweight, RepoInterface, path_based_str_repr
  from datalad.runner.nonasyncrunner import STDERR_FILENO, STDOUT_FILENO
  from datalad.runner.protocol import GeneratorMixIn
  from datalad.runner.utils import AssemblingDecoderMixIn, LineSplitter
  from datalad.support.exceptions import CommandError, GitIgnoreError, InvalidGitRepositoryError, PathKnownToRepositoryError
  from datalad.utils import ensure_list, lock_if_required, Path
label_desc: Use image node_id 10 for calling the GitRepo obj's underlying member method code with example usage: obj.add_fake_dates_to_env(env) and returns: env