code: def test_ellipsoidal_cs():
      ellipsoidal_cs = {
          "type": "CoordinateSystem",
          "subtype": "ellipsoidal",
          "axis": [
              {
                  "name": "Latitude",
                  "abbreviation": "lat",
                  "direction": "north",
                  "unit": "degree",
              },
              {
                  "name": "Longitude",
                  "abbreviation": "lon",
                  "direction": "east",
                  "unit": "degree",
              },
          ],
      }
      crs = CRS.from_cf(
          dict(
              grid_mapping_name="latitude_longitude",
              semi_major_axis=6378137.0,
              inverse_flattening=298.257223,
          ),
          ellipsoidal_cs=ellipsoidal_cs,
      )
      json_dict = crs.coordinate_system.to_json_dict()
      json_dict.pop("$schema")
      assert json_dict == ellipsoidal_cs
      # test coordinate system
      assert crs.cs_to_cf() == [
          {
              "standard_name": "latitude",
              "long_name": "latitude coordinate",
              "units": "degrees_north",
              "axis": "Y",
          },
          {
              "standard_name": "longitude",
              "long_name": "longitude coordinate",
              "units": "degrees_east",
              "axis": "X",
          },
      ]
  
imports: import numpy
  import pytest
  from numpy.testing import assert_almost_equal
  from packaging import version
  from pyproj import CRS
  from pyproj.crs import ProjectedCRS
  from pyproj.crs._cf1x8 import _try_list_if_string
  from pyproj.crs.coordinate_operation import LambertAzimuthalEqualAreaConversion, LambertCylindricalEqualAreaConversion, MercatorAConversion, OrthographicConversion, PolarStereographicAConversion, PolarStereographicBConversion, SinusoidalConversion, StereographicConversion, VerticalPerspectiveConversion
  from pyproj.exceptions import CRSError
  from test.conftest import PROJ_GTE_901, PROJ_LOOSE_VERSION
label_desc: Use image node_id 42 for calling a global function with example usage: test_ellipsoidal_cs() without return types