<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def load_map_coordinates(map_file):
 """ Loads map coordinates from netCDF or pickle file created by util.makeMapGrids. Args: map_file: Filename for the file containing coordinate information. Returns: Latitude and longitude grids as numpy arrays. """

    if map_file[-4:] == ".pkl":
        map_data = pickle.load(open(map_file))
        lon = map_data['lon']
        lat = map_data['lat']
    else:
        map_data = Dataset(map_file)
        if "lon" in map_data.variables.keys():
            lon = map_data.variables['lon'][:]
            lat = map_data.variables['lat'][:]
        else:
            lon = map_data.variables["XLONG"][0]
            lat = map_data.variables["XLAT"][0]
    return lon, lat