code: def test_cohn(self):
      cols = [
          "nuncen_above",
          "nobs_below",
          "ncen_equal",
          "prob_exceedance",
      ]
      cohn = ros.cohn_numbers(self.df, self.rescol, self.cencol)
      # Use round in place of the deprecated check_less_precise arg
      assert_frame_equal(
          np.round(cohn[cols], 3),
          np.round(self.expected_cohn[cols], 3),
      )
  
imports: from statsmodels.compat.pandas import assert_series_equal, assert_frame_equal
  from io import StringIO
  from textwrap import dedent
  import numpy
  import numpy.testing
  import numpy
  from numpy.testing import assert_equal
  import pandas
  import pytest
  from statsmodels.imputation import ros
label_desc: Use image node_id 3 for calling the CheckROSMixin obj's underlying member method code with example usage: obj.test_cohn() without return types