code: def test_nan(oblique_mercator, plate_carree, reverse_coord):
      coord = (0.0, np.NaN)
      if reverse_coord:
          coord = tuple(reversed(coord))
      res = oblique_mercator.transform_point(
          *coord, src_crs=plate_carree
      )
      assert np.all(np.isnan(res))
  
file_path: cartopy/lib/cartopy/tests/crs/test_oblique_mercator.py
imports: from copy import deepcopy
  from typing import Dict, List, NamedTuple, Tuple
  import numpy
  import pytest
  import cartopy.crs
  from .helpers import check_proj_params
label_desc: Use image node_id 6 for calling a global function with example usage: test_nan(oblique_mercator, plate_carree, reverse_coord) without return types