code: def test_lonlatformatter_cardinal_labels():
      xticker = LongitudeFormatter(cardinal_labels={"west": "O"})
      yticker = LatitudeFormatter(cardinal_labels={"south": "South"})
      assert xticker(-10) == "10°O"
      assert yticker(-10) == "10°South"
  
imports: from unittest.mock import Mock
  import matplotlib.pyplot
  import numpy
  import pytest
  import cartopy.crs
  from cartopy.mpl.geoaxes import GeoAxes
  from cartopy.mpl.ticker import LatitudeFormatter, LatitudeLocator, LongitudeFormatter, LongitudeLocator
label_desc: Use image node_id 19 for calling a global function with example usage: test_lonlatformatter_cardinal_labels() without return types