code: def test_pickle(proj_to_copy):
      # check that we can pickle a simple CRS
      fh = BytesIO()
      pickle.dump(proj_to_copy, fh)
      fh.seek(0)
      pickled_prj = pickle.load(fh)
      assert proj_to_copy == pickled_prj
  
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 a global function with example usage: test_pickle(proj_to_copy) without return types