docs: def is_existing_up_to_date(destination, latest_version):
      """Returns False if there is no existing install or if the existing install
      is out of date. Otherwise, returns True."""
      version_path = os.path.join(
          destination, 'google_appengine', 'VERSION')
  
      if not os.path.exists(version_path):
          return False
  
      with open(version_path, 'r') as f:
          version_line = f.readline()
  
          match = SDK_RELEASE_RE.match(version_line)
  
          if not match:
              print('Unable to parse version from:', version_line)
              return False
  
          version = [int(x) for x in match.groups()]
  
      return version >= latest_version