code: def test_cov1d(data1, data2):
      gs1 = cudf.Series(data1)
      gs2 = cudf.Series(data2)
  
      ps1 = gs1.to_pandas()
      ps2 = gs2.to_pandas()
  
      got = gs1.cov(gs2)
      ps1_align, ps2_align = ps1.align(ps2, join="inner")
      with expect_warning_if(
          (len(ps1_align.dropna()) == 1 and len(ps2_align.dropna()) > 0)
          or (
              len(ps2_align.dropna()) == 1
              and len(ps1_align.dropna()) > 0
          ),
          RuntimeWarning,
      ):
          expected = ps1.cov(ps2)
      np.testing.assert_approx_equal(got, expected, significant=8)
  
imports: from concurrent.futures import ThreadPoolExecutor
  import cupy
  import numpy
  import pandas
  import pytest
  import cudf
  from cudf.datasets import randomdata
  from cudf.testing._utils import _create_cudf_series_float64_default, _create_pandas_series_float64_default, assert_eq, assert_exceptions_equal, expect_warning_if
label_desc: Use image node_id 17 for calling a global function with example usage: test_cov1d(data1, data2) without return types