code: def setup_method(self):
      self.results = sm.OLS.from_formula(
          "Y ~ A + B + C", data=self.data
      ).fit()
  
imports: from statsmodels.compat.pandas import assert_series_equal
  from io import BytesIO
  import pickle
  import numpy
  import pandas
  import statsmodels.api
label_desc: Use image node_id 2 for calling the TestPickleFormula2 obj's underlying member method code with example usage: obj.setup_method() without return types