docstr: Get the most recent ancestor of HEAD that occurs on an upstream branch.
  
  First looks at the current branch's tracking branch, if applicable. If
  that doesn't work, looks at every other branch to find the most recent
  ancestor of HEAD that occurs on a tracking branch.
  
  Returns:
      git.Commit object or None
docstr_tok: ["Get","the","most","recent","ancestor","of","HEAD","that","occurs","on","an","upstream","branch",".","First","looks","at","the","current","branch","'s","tracking","branch",",","if","applicable",".","If","that","does","n't","work",",","looks","at","every","other","branch","to","find","the","most","recent","ancestor","of","HEAD","that","occurs","on","a","tracking","branch",".","Returns",":","git.Commit","object","or","None"]
code: def get_upstream_fork_point(self) -> Any:
      """Get the most recent ancestor of HEAD that occurs on an upstream branch.
  
      First looks at the current branch's tracking branch, if applicable. If
      that doesn't work, looks at every other branch to find the most recent
      ancestor of HEAD that occurs on a tracking branch.
  
      Returns:
          git.Commit object or None
      """
      possible_relatives = []
      try:
          if not self.repo:
              return None
          try:
              active_branch = self.repo.active_branch
          except (TypeError, ValueError):
              logger.debug("git is in a detached head state")
              return None  # detached head
          else:
              tracking_branch = active_branch.tracking_branch()
              if tracking_branch:
                  possible_relatives.append(tracking_branch.commit)
  
          if not possible_relatives:
              for branch in self.repo.branches:
                  tracking_branch = branch.tracking_branch()
                  if tracking_branch is not None:
                      possible_relatives.append(tracking_branch.commit)
  
          head = self.repo.head
          most_recent_ancestor = None
          for possible_relative in possible_relatives:
              # at most one:
              for ancestor in self.repo.merge_base(
                  head, possible_relative
              ):
                  if most_recent_ancestor is None:
                      most_recent_ancestor = ancestor
                  elif self.repo.is_ancestor(most_recent_ancestor, ancestor):  # type: ignore
                      most_recent_ancestor = ancestor
          return most_recent_ancestor
      except GitCommandError as e:
          logger.debug(
              "git remote upstream fork point could not be found"
          )
          logger.debug(str(e))
          return None
  
imports: import configparser
  import logging
  import os
  from typing import TYPE_CHECKING, Any, Optional
  from urllib.parse import urlparse, urlunparse
  import wandb
label_desc: Use image node_id 16 for calling the GitRepo obj's underlying member method code with example usage: obj.get_upstream_fork_point() and returns: most_recent_ancestor, None, None, None