code: def test_regression_with_tuples(self):
      i = pandas.Series([1, 2, 3, 4] * 10, name="i")
      y = pandas.Series([1, 2, 3, 4, 5] * 8, name="y")
      x = pandas.Series([1, 2, 3, 4, 5, 6, 7, 8] * 5, name="x")
  
      df = pandas.DataFrame(index=i.index)
      df = df.join(i)
      endo = df.join(y)
      exo = df.join(x)
      endo_groups = endo.groupby("i")
      exo_groups = exo.groupby("i")
      exo_df = exo_groups.agg(["sum", "max"])
      endo_df = endo_groups.agg(["sum", "max"])
      reg = OLS(exo_df[[("x", "sum")]], endo_df).fit()
      interesting_lines = []
      import warnings
  
      with warnings.catch_warnings():
          # Catch ominormal warning, not interesting here
          warnings.simplefilter("ignore")
          for line in str(reg.summary()).splitlines():
              if "_" in line:
                  interesting_lines.append(line[:38])
  
      desired = [
          "Dep. Variable:                  x_sum ",
          "y_sum          1.4595      0.209      ",
          "y_max          0.2432      0.035      ",
      ]
  
      assert_equal(sorted(desired), sorted(interesting_lines))
  
file_path: statsmodels/statsmodels/iolib/tests/test_table.py
imports: from numpy.testing import assert_equal
  from statsmodels.iolib.table import SimpleTable, default_txt_fmt
  from statsmodels.iolib.table import default_latex_fmt
  from statsmodels.iolib.table import default_html_fmt
  import pandas
  from statsmodels.regression.linear_model import OLS
label_desc: Use image node_id 6 for calling the TestSimpleTable obj's underlying member method code with example usage: obj.test_regression_with_tuples() without return types