docs: def normalize_lat_lng(arg):
      """Take the various lat/lng representations and return a tuple.
  
      Accepts various representations:
      1) dict with two entries - "lat" and "lng"
      2) list or tuple - e.g. (-33, 151) or [-33, 151]
  
      :param arg: The lat/lng pair.
      :type arg: dict or list or tuple
  
      :rtype: tuple (lat, lng)
      """
      if isinstance(arg, dict):
          if "lat" in arg and "lng" in arg:
              return arg["lat"], arg["lng"]
          if "latitude" in arg and "longitude" in arg:
              return arg["latitude"], arg["longitude"]
  
      # List or tuple.
      if _is_list(arg):
          return arg[0], arg[1]
  
      raise TypeError(
          "Expected a lat/lng dict or tuple, "
          "but got %s" % type(arg).__name__)