code: def test_summarycol_drop_omitted(self):
      # gh-3702
      x = [1, 5, 7, 3, 5]
      x = add_constant(x)
      x2 = np.concatenate([x, np.array([[3], [9], [-1], [4], [0]])], 1)
      y1 = [6, 4, 2, 7, 4]
      y2 = [8, 5, 0, 12, 4]
      reg1 = OLS(y1, x).fit()
      reg2 = OLS(y2, x2).fit()
      actual = summary_col(
          [reg1, reg2],
          regressor_order=["const", "x1"],
          drop_omitted=True,
      )
      assert "x2" not in str(actual)
      actual = summary_col(
          [reg1, reg2], regressor_order=["x1"], drop_omitted=False
      )
      assert "const" in str(actual)
      assert "x2" in str(actual)
  
file_path: statsmodels/statsmodels/iolib/tests/test_summary2.py
imports: import warnings
  import numpy
  import pandas
  import pytest
  from numpy.testing import assert_equal
  from statsmodels.iolib.summary2 import summary_col
  from statsmodels.tools.tools import add_constant
  from statsmodels.regression.linear_model import OLS
label_desc: Use image node_id 3 for calling the TestSummaryLatex obj's underlying member method code with example usage: obj.test_summarycol_drop_omitted() without return types