code: def test_wrong_len_xname(reset_randomstate):
      y = np.random.randn(100)
      x = np.random.randn(100, 2)
      res = OLS(y, x).fit()
      with pytest.raises(ValueError):
          res.summary(xname=["x1"])
      with pytest.raises(ValueError):
          res.summary(xname=["x1", "x2", "x3"])
  
file_path: statsmodels/statsmodels/iolib/tests/test_summary.py
imports: import numpy
  import pytest
  from numpy.testing import assert_equal
  from statsmodels.datasets import macrodata
  from statsmodels.tools.tools import add_constant
  from statsmodels.regression.linear_model import OLS
label_desc: Use image node_id 2 for calling a global function with example usage: test_wrong_len_xname(reset_randomstate) without return types