code: def test_to_cf_transverse_mercator():
      crs = CRS(
          proj="tmerc",
          lat_0=0,
          lon_0=15,
          k=0.9996,
          x_0=2520000,
          y_0=0,
          ellps="intl",
          units="m",
          towgs84="-122.74,-34.27,-22.83,-1.884,-3.400,-3.030,-15.62",
      )
      towgs84_test = [
          -122.74,
          -34.27,
          -22.83,
          -1.884,
          -3.4,
          -3.03,
          -15.62,
      ]
      horizontal_datum_name = "Unknown based on International 1924 (Hayford 1909, 1910) ellipsoid"
      if PROJ_GTE_901:
          horizontal_datum_name = (
              f"{horizontal_datum_name} using "
              "towgs84=-122.74,-34.27,-22.83,-1.884,-3.400,-3.030,-15.62"
          )
      expected_cf = {
          "semi_major_axis": 6378388.0,
          "semi_minor_axis": crs.ellipsoid.semi_minor_metre,
          "inverse_flattening": 297.0,
          "reference_ellipsoid_name": "International 1924 (Hayford 1909, 1910)",
          "longitude_of_prime_meridian": 0.0,
          "prime_meridian_name": "Greenwich",
          "horizontal_datum_name": horizontal_datum_name,
          "towgs84": towgs84_test,
          "grid_mapping_name": "transverse_mercator",
          "latitude_of_projection_origin": 0.0,
          "longitude_of_central_meridian": 15.0,
          "false_easting": 2520000.0,
          "false_northing": 0.0,
          "scale_factor_at_central_meridian": 0.9996,
          "geographic_crs_name": "unknown",
          "projected_crs_name": "unknown",
      }
      cf_dict = crs.to_cf()
      assert cf_dict.pop("crs_wkt").startswith("BOUNDCRS[")
      assert cf_dict == expected_cf
      # test roundtrip
      _test_roundtrip(expected_cf, "BOUNDCRS[")
      # test coordinate system
      assert crs.cs_to_cf() == [
          {
              "axis": "X",
              "long_name": "Easting",
              "standard_name": "projection_x_coordinate",
              "units": "metre",
          },
          {
              "axis": "Y",
              "long_name": "Northing",
              "standard_name": "projection_y_coordinate",
              "units": "metre",
          },
      ]
  
      with pytest.warns(UserWarning):
          assert crs.to_dict() == {
              "proj": "tmerc",
              "lat_0": 0,
              "lon_0": 15,
              "k": 0.9996,
              "x_0": 2520000,
              "y_0": 0,
              "ellps": "intl",
              "towgs84": towgs84_test,
              "units": "m",
              "no_defs": None,
              "type": "crs",
          }
  
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 4 for calling a global function with example usage: test_to_cf_transverse_mercator() without return types