code: def git_branch_info_to_track():
      """Obtains the remote branch name, remote name, and commit hash that
      should be tracked for changes.
  
      Returns:
          ("refs/heads/mybranch", "origin", "1A2B3C4...")
      """
      expected_sha = None
      ref = None
      remote = git("remote", "show", "-n").splitlines()[0]
  
      ci = get_current_ci()
      if ci == GITHUB:
          expected_sha = (
              os.getenv("GITHUB_HEAD_SHA") or os.environ["GITHUB_SHA"]
          )
          ref = replace_suffix(
              os.environ["GITHUB_REF"], "/merge", "/head"
          )
      elif ci == TRAVIS:
          pr = os.getenv("TRAVIS_PULL_REQUEST", "false")
          if pr != "false":
              expected_sha = os.environ["TRAVIS_PULL_REQUEST_SHA"]
              ref = "refs/pull/{}/head".format(pr)
          else:
              expected_sha = os.environ["TRAVIS_COMMIT"]
              ref = "refs/heads/{}".format(os.environ["TRAVIS_BRANCH"])
  
      result = (ref, remote, expected_sha)
  
      if not all(result):
          msg = (
              "Invalid remote {!r}, ref {!r}, or hash {!r} for CI {!r}"
          )
          raise ValueError(msg.format(remote, ref, expected_sha, ci))
  
      return result
  
imports: import argparse
  import errno
  import logging
  import os
  import signal
  import subprocess
  import sys
  import time
label_desc: Use image node_id 7 for calling a global function with example usage: git_branch_info_to_track() and returns: result