code: def _git_command(params, cwd):
      
  
      proc = subprocess.Popen(
          ['git'] + params,
          stdout=subprocess.PIPE,
          stderr=subprocess.STDOUT,
          cwd=cwd
      )
      stdout, stderr = proc.communicate()
      code = proc.wait()
      if code != 0:
          e = OSError('git exit code was non-zero')
          e.stdout = stdout
          raise e
      return stdout.decode('utf-8').strip()
docs: Executes a git command, returning the output
  
      :param params:
          A list of the parameters to pass to git
  
      :param cwd:
          The working directory to execute git in
  
      :return:
          A 2-element tuple of (stdout, stderr)