code: def test_osni(self, approx):
      osni = ccrs.OSNI(approx=approx)
      ll = ccrs.Geodetic()
  
      # results obtained by nearby.org.uk.
      lat, lon = np.array(
          [54.5622169298669, -5.54159863617957], dtype=np.double
      )
      east, north = np.array([359000, 371000], dtype=np.double)
  
      assert_arr_almost_eq(
          osni.transform_point(lon, lat, ll),
          np.array([east, north]),
          -1,
      )
      assert_arr_almost_eq(
          ll.transform_point(east, north, osni), np.array([lon, lat]), 3
      )
  
imports: import copy
  from io import BytesIO
  import os
  from pathlib import Path
  import pickle
  import warnings
  import numpy
  from numpy.testing import assert_almost_equal, assert_array_equal
  from numpy.testing import assert_array_almost_equal
  import pyproj
  import pytest
  import shapely.geometry
  import cartopy.crs
label_desc: Use image node_id 2 for calling the TestCRS obj's underlying member method code with example usage: obj.test_osni(approx) without return types